UNITED STATES
SECURITIES AND EXCHANGE COMMISSION
Washington, DC 20549

FORM N-Q

QUARTERLY SCHEDULE OF PORTFOLIO HOLDINGS OF REGISTERED MANAGEMENT INVESTMENT COMPANY

Investment Company Act file number         811-6693         

        Nuveen Select Tax-Free Income Portfolio 3         
(Exact name of registrant as specified in charter)

Nuveen Investments
        333 West Wacker Drive, Chicago, Illinois 60606         
(Address of principal executive offices) (Zip code)

Kevin J. McCarthy Vice President and Secretary
        333 West Wacker Drive, Chicago, Illinois 60606         
(Name and address of agent for service)

Registrant's telephone number, including area code:         312-917-7700        

Date of fiscal year end:            3/31          

Date of reporting period:         6/30/08         

Form N-Q is to be used by management investment companies, other than small business investment companies registered on Form N-5 (§§ 239.24 and 274.5 of this chapter), to file reports with the Commission, not later than 60 days after the close of the first and third fiscal quarters, pursuant to rule 30b1-5 under the Investment Company Act of 1940 (17 CFR 270.30b1-5). The Commission may use the information provided on Form N-Q in its regulatory, disclosure review, inspection, and policymaking roles.

A registrant is required to disclose the information specified by Form N-Q, and the Commission will make this information public. A registrant is not required to respond to the collection of information contained in Form N-Q unless the Form displays a currently valid Office of Management and Budget ("OMB") control number. Please direct comments concerning the accuracy of the information collection burden estimate and any suggestions for reducing the burden to the Secretary, Securities and Exchange Commission, 450 Fifth Street, NW, Washington, DC 20549-0609. The OMB has reviewed this collection of information under the clearance requirements of 44 U.S.C. § 3507.

Item 1. Schedule of Investments

		Portfolio of Investments (Unaudited)
		Nuveen Select Tax-Free Income Portfolio 3 (NXR)
		June 30, 2008
Principal				Optional Call
Amount (000)		Description (1)		Provisions (2)		Ratings (3)		Value
		Municipal Bonds – 98.1%
		Alabama – 0.3%
$            500		Marshall County Healthcare Authority, Alabama, Revenue Bonds, Series 2002A, 6.250%, 1/01/22		1/12 at 101.00		A–	$	521,445
		California – 7.2%
2,105		Azusa Unified School District, Los Angeles County, California, General Obligation Bonds,		7/12 at 100.00		AAA		2,219,428
		Series 2002, 5.375%, 7/01/21 – FSA Insured
1,000		California County Tobacco Securitization Agency, Tobacco Settlement Asset-Backed Bonds, Los		12/18 at 100.00		Baa3		691,280
		Angeles County Securitization Corporation, Series 2006A, 0.000%, 6/01/36 (Mandatory
		put 6/01/23)
3,350		California Department of Water Resources, Power Supply Revenue Bonds, Series 2002A,		5/12 at 101.00		Aa3		3,660,914
		6.000%, 5/01/14
2,595		California Health Facilities Financing Authority, Revenue Bonds, Kaiser Permanante System,		4/16 at 100.00		A+		2,442,310
		Series 2006, 5.000%, 4/01/37
420		Golden State Tobacco Securitization Corporation, California, Enhanced Tobacco Settlement		6/17 at 100.00		BBB		375,207
		Asset-Backed Bonds, Series 2007A-1, 4.500%, 6/01/27
3,000		Golden State Tobacco Securitization Corporation, California, Tobacco Settlement Asset-Backed		6/13 at 100.00		AAA		3,401,190
		Bonds, Series 2003A-1, 6.750%, 6/01/39 (Pre-refunded 6/01/13)
250		Santa Ana Unified School District, Orange County, California, General Obligation Bonds, Series		8/10 at 101.00		A+		260,003
		2000, 5.700%, 8/01/29 – FGIC Insured
12,720		Total California						13,050,332
		Colorado – 6.6%
1,540		Arkansas River Power Authority, Colorado, Power Revenue Bonds, Series 2006, 5.250%, 10/01/40 –		10/16 at 100.00		BBB		1,363,624
		XLCA Insured
400		Colorado Department of Transportation, Certificates of Participation, Series 2004, 5.000%,		6/14 at 100.00		AA		402,036
		6/15/34 – MBIA Insured
2,265		Colorado Health Facilities Authority, Revenue Bonds, Catholic Health Initiatives, Series 2002A,		3/12 at 100.00		AA (4)		2,388,443
		5.500%, 3/01/22 (ETM)
1,735		Colorado Health Facilities Authority, Revenue Bonds, Catholic Health Initiatives, Series 2002A,		3/12 at 100.00		AA (4)		1,867,190
		5.500%, 3/01/22 (Pre-refunded 3/01/12)
2,395		Denver City and County, Colorado, Airport System Revenue Bonds, Series 1991D, 7.750%, 11/15/13		No Opt. Call		A+		2,636,656
		(Alternative Minimum Tax)
3,000		Denver Convention Center Hotel Authority, Colorado, Senior Revenue Bonds, Convention Center		12/13 at 100.00		N/R (4)		3,186,510
		Hotel, Series 2003A, 5.000%, 12/01/24 (Pre-refunded 12/01/13) – XLCA Insured
11,335		Total Colorado						11,844,459
		Connecticut – 0.2%
250		Connecticut Health and Educational Facilities Authority, Revenue Bonds, Bridgeport Hospital		7/08 at 100.00		AA		251,178
		Issue, Series 1992A, 6.625%, 7/01/18 – MBIA Insured
		District of Columbia – 0.2%
15		District of Columbia, General Obligation Bonds, Series 1993E, 6.000%, 6/01/13 – MBIA Insured (ETM)		9/08 at 100.00		AAA		15,044
235		District of Columbia, General Obligation Refunding Bonds, Series 1994A-1, 6.500%, 6/01/10 –		No Opt. Call		AAA		249,779
		MBIA Insured
250		Total District of Columbia						264,823
		Florida – 5.6%
1,000		Hillsborough County Industrial Development Authority, Florida, Hospital Revenue Bonds, Tampa		10/16 at 100.00		A3		945,930
		General Hospital, Series 2006, 5.250%, 10/01/41
5,020		JEA St. John’s River Power Park System, Florida, Revenue Refunding Bonds, Issue 2, Series 2002-17,		10/11 at 100.00		Aa2		5,170,599
		5.000%, 10/01/18
4,000		JEA, Florida, Subordinate Lien Electric System Revenue Bonds, Series 2002D, 4.625%, 10/01/22		9/08 at 100.00		Aa3		3,985,280
10,020		Total Florida						10,101,809
		Georgia – 0.3%
545		Atlanta, Georgia, Airport Facilities Revenue Bonds, Series 1990, 0.000%, 1/01/10 – MBIA		No Opt. Call		AA		508,736
		Insured (Alternative Minimum Tax)
		Illinois – 18.2%
115		Chicago Metropolitan Housing Development Corporation, Illinois, FHA-Insured Section 8 Assisted		7/08 at 100.00		AA		118,934
		Housing Development Revenue Refunding Bonds, Series 1992, 6.850%, 7/01/22
1,930		Illinois Development Finance Authority, Revenue Bonds, Midwestern University, Series 2001B,		5/11 at 101.00		AAA		2,090,576
		5.750%, 5/15/16 (Pre-refunded 5/15/11)
525		Illinois Finance Authority, Revenue Bonds, Loyola University of Chicago, Tender Option Bond		7/17 at 100.00		AA		521,693
		Trust 1137, 14.084%, 7/01/46 (IF)
2,185		Illinois Finance Authority, Revenue Bonds, YMCA of Southwest Illinois, Series 2005, 5.000%,		9/15 at 100.00		Aa3		2,023,834
		9/01/31 – RAAI Insured
4,450		Illinois Health Facilities Authority, Remarketed Revenue Bonds, University of Chicago Project,		8/11 at 103.00		Aa1		4,669,786
		Series 1985A, 5.500%, 8/01/20
1,500		Illinois Health Facilities Authority, Revenue Bonds, Evangelical Hospitals Corporation, Series		No Opt. Call		N/R (4)		1,773,900
		1992C, 6.250%, 4/15/22 (ETM)
2,225		Illinois Health Facilities Authority, Revenue Refunding Bonds, Elmhurst Memorial Healthcare,		1/13 at 100.00		Baa1		2,319,518
		Series 2002, 6.250%, 1/01/17
2,500		Illinois Housing Development Authority, Homeowner Mortgage Revenue Bonds, Series 2006C2,		2/16 at 100.00		AA		2,407,975
		5.050%, 8/01/27 (Alternative Minimum Tax)
5,700		Illinois, Sales Tax Revenue Bonds, First Series 2002, 5.000%, 6/15/22		6/13 at 100.00		AAA		5,853,329
2,000		Illinois, Sales Tax Revenue Bonds, Series 1997X, 5.600%, 6/15/17		12/08 at 100.50		AAA		2,015,080
1,000		Kankakee & Will Counties Community Unit School District 5, Illinois, General Obligation Bonds,		No Opt. Call		Aaa		474,400
		Series 2006, 0.000%, 5/01/23 – FSA Insured
6,000		Metropolitan Pier and Exposition Authority, Illinois, Revenue Refunding Bonds, McCormick Place		6/12 at 101.00		AAA		6,166,739
		Expansion Project, Series 2002B, 5.000%, 6/15/21 – MBIA Insured
1,300		Schaumburg, Illinois, General Obligation Bonds, Series 2004B, 5.250%, 12/01/34 – FGIC Insured		12/14 at 100.00		AA+		1,324,037
1,000		Yorkville, Illinois, General Obligation Debt Certificates, Series 2003, 5.000%, 12/15/22		12/11 at 100.00		A (4)		1,061,300
		(Pre-refunded 12/15/11) – RAAI Insured
32,430		Total Illinois						32,821,101
		Indiana – 6.4%
1,000		Franklin Community Multi-School Building Corporation, Marion County, Indiana, First Mortgage		7/14 at 100.00		A (4)		1,080,640
		Revenue Bonds, Series 2004, 5.000%, 7/15/22 (Pre-refunded 7/15/14) – FGIC Insured
3,500		Indiana Health Facility Financing Authority, Hospital Revenue Bonds, Methodist Hospitals Inc.,		9/11 at 100.00		BBB+		3,248,245
		Series 2001, 5.375%, 9/15/22
2,500		Indiana Health Facility Financing Authority, Hospital Revenue Refunding Bonds, Columbus		No Opt. Call		AAA		2,823,100
		Regional Hospital, Series 1993, 7.000%, 8/15/15 – FSA Insured
2,000		Indianapolis Local Public Improvement Bond Bank, Indiana, Waterworks Project, Series 2002A,		7/12 at 100.00		AAA		2,147,840
		5.250%, 7/01/33 (Pre-refunded 7/01/12) – MBIA Insured
2,295		Shelbyville Central Renovation School Building Corporation, Indiana, First Mortgage Bonds,		7/15 at 100.00		AA		2,200,354
		Series 2005, 4.375%, 7/15/25 – MBIA Insured
11,295		Total Indiana						11,500,179
		Iowa – 5.7%
2,745		Iowa Finance Authority, Health Facility Revenue Bonds, Care Initiatives Project, Series 2006A,		7/16 at 100.00		BBB–		2,431,713
		5.000%, 7/01/20
750		Iowa Tobacco Settlement Authority, Tobacco Asset-Backed Revenue Bonds, Series 2005B,		6/17 at 100.00		BBB		671,918
		5.600%, 6/01/34
		Iowa Tobacco Settlement Authority, Tobacco Settlement Asset-Backed Revenue Bonds, Series 2001B:
3,850		5.300%, 6/01/25 (Pre-refunded 6/01/11)		6/11 at 101.00		AAA		4,089,008
2,850		5.600%, 6/01/35 (Pre-refunded 6/01/11)		6/11 at 101.00		AAA		3,061,385
10,195		Total Iowa						10,254,024
		Kansas – 1.2%
		Lawrence, Kansas, Hospital Revenue Bonds, Lawrence Memorial Hospital, Series 2006:
1,425		5.125%, 7/01/26		7/16 at 100.00		A3		1,425,000
700		4.875%, 7/01/36		7/16 at 100.00		A3		645,827
2,125		Total Kansas						2,070,827
		Maine – 0.7%
125		Maine Health and Higher Educational Facilities Authority, Revenue Bonds, Series 1999B, 6.000%,		7/09 at 101.00		Aaa		129,355
		7/01/19 – MBIA Insured
1,075		Maine Health and Higher Educational Facilities Authority, Revenue Bonds, Series 1999B, 6.000%,		7/09 at 101.00		Aaa		1,130,728
		7/01/19 (Pre-refunded 7/01/09) – MBIA Insured
1,200		Total Maine						1,260,083
		Massachusetts – 0.8%
1,000		Massachusetts Development Finance Agency, Resource Recovery Revenue Bonds, Ogden Haverhill		12/08 at 102.00		BBB		980,330
		Associates, Series 1998B, 5.200%, 12/01/13 (Alternative Minimum Tax)
15		Massachusetts Health and Educational Facilities Authority, Revenue Bonds, Partners HealthCare		7/11 at 101.00		AA		16,164
		System Inc., Series 2001C, 6.000%, 7/01/17
485		Massachusetts Health and Educational Facilities Authority, Revenue Bonds, Partners HealthCare		7/11 at 101.00		AAA		530,115
		System Inc., Series 2001C, 6.000%, 7/01/17 (Pre-refunded 7/01/11)
1,500		Total Massachusetts						1,526,609
		Michigan – 3.4%
1,500		Detroit, Michigan, Sewer Disposal System Revenue Bonds, Second Lien, Series 2006B, 4.625%,		7/16 at 100.00		A		1,364,865
		7/01/34 – FGIC Insured
2,900		Michigan State Hospital Finance Authority, Hospital Revenue Refunding Bonds, Trinity Health		12/12 at 100.00		AA		2,939,092
		Credit Group, Series 2002C, 5.375%, 12/01/30
235		Michigan State Hospital Finance Authority, Revenue Refunding Bonds, Detroit Medical Center		8/08 at 100.00		BB–		235,066
		Obligated Group, Series 1993A, 6.500%, 8/15/18
1,600		Plymouth-Canton Community School District, Wayne and Washtenaw Counties, Michigan, Unlimited		5/09 at 100.00		AA– (4)		1,640,032
		Tax General Obligation School Building and Site Bonds, Series 1999, 4.750%, 5/01/18
		(Pre-refunded 5/01/09)
6,235		Total Michigan						6,179,055
		Mississippi – 0.4%
725		Mississippi Hospital Equipment and Facilities Authority, Revenue Bonds, Baptist Memorial		9/14 at 100.00		AA		718,606
		Healthcare, Series 2004B-1, 5.000%, 9/01/24
		Nebraska – 1.9%
3,500		Nebraska Public Power District, General Revenue Bonds, Series 2002B, 5.000%, 1/01/33 –		1/13 at 100.00		AA		3,446,520
		AMBAC Insured
		Nevada – 4.2%
4,095		Director of Nevada State Department of Business and Industry, Revenue Bonds, Las Vegas		1/10 at 100.00		AA		2,774,772
		Monorail Project, First Tier, Series 2000, 5.375%, 1/01/40 – AMBAC Insured
1,680		Reno, Nevada, Capital Improvement Revenue Bonds, Series 2002, 5.500%, 6/01/22 – FGIC Insured		6/12 at 100.00		Baa1		1,694,028
2,830		Reno, Nevada, Capital Improvement Revenue Bonds, Series 2002, 5.500%, 6/01/22 (Pre-refunded		6/12 at 100.00		Baa1 (4)		3,051,872
		6/01/12) – FGIC Insured
8,605		Total Nevada						7,520,672
		New Hampshire – 0.3%
480		New Hampshire Housing Finance Authority, Single Family Mortgage Acquisition Bonds, Series		5/11 at 100.00		Aa2		489,859
		2001A, 5.600%, 7/01/21 (Alternative Minimum Tax)
		New Jersey – 1.5%
		Tobacco Settlement Financing Corporation, New Jersey, Tobacco Settlement Asset-Backed Bonds,
		Series 2003:
1,000		6.750%, 6/01/39 (Pre-refunded 6/01/13)		6/13 at 100.00		AAA		1,145,820
1,355		6.250%, 6/01/43 (Pre-refunded 6/01/13)		6/13 at 100.00		AAA		1,522,207
2,355		Total New Jersey						2,668,027
		New Mexico – 2.7%
1,000		New Mexico Mortgage Finance Authority, Multifamily Housing Revenue Bonds, St Anthony, Series		9/17 at 100.00		AAA		936,810
		2007A, 5.250%, 9/01/42 (Alternative Minimum Tax)
4,000		University of New Mexico, FHA-Insured Mortgage Hospital Revenue Bonds, Series 2004, 4.625%,		7/14 at 100.00		AAA		3,938,760
		1/01/25 – FSA Insured
5,000		Total New Mexico						4,875,570
		New York – 3.0%
815		Dormitory Authority of the State of New York, Second General Resolution Consolidated Revenue		No Opt. Call		A1		853,753
		Bonds, City University System, Series 1990C, 7.500%, 7/01/10
250		Dormitory Authority of the State of New York, FHA-Insured State Personal Income Tax Revenue		8/16 at 100.00		AA		181,035
		Bonds, Tender Option Bond Trust 2846, 13.041%, 2/15/35 (IF)
2,335		Long Island Power Authority, New York, Electric System General Revenue Bonds, Series 2001A,		9/11 at 100.00		AAA		2,503,213
		5.375%, 9/01/21 (Pre-refunded 9/01/11)
35		New York City, New York, General Obligation Bonds, Series 1991B, 7.000%, 2/01/18		9/08 at 100.00		AA		35,127
1,850		New York State Tobacco Settlement Financing Corporation, Tobacco Settlement Asset-Backed and		6/10 at 100.00		AA–		1,899,340
		State Contingency Contract-Backed Bonds, Series 2003B-1C, 5.500%, 6/01/15
5,285		Total New York						5,472,468
		North Carolina – 4.2%
5,000		North Carolina Municipal Power Agency 1, Catawba Electric Revenue Bonds, Series 2003A, 5.250%,		1/13 at 100.00		AA		5,141,649
		1/01/18 – MBIA Insured
2,345		Piedmont Triad Airport Authority, North Carolina, Airport Revenue Bonds, Series 2001A, 5.250%,		7/11 at 101.00		AAA		2,465,533
		7/01/16 – FSA Insured
7,345		Total North Carolina						7,607,182
		Oklahoma – 1.7%
3,000		Oklahoma Development Finance Authority, Revenue Bonds, St. John Health System, Series 2004,		2/14 at 100.00		AA–		2,999,820
		5.000%, 2/15/24
		Pennsylvania – 2.4%
2,435		Dauphin County Industrial Development Authority, Pennsylvania, Water Development Revenue		No Opt. Call		A–		2,867,797
		Refunding Bonds, Dauphin Consolidated Water Supply Company, Series 1992B, 6.700%, 6/01/17
500		Pennsylvania Higher Educational Facilities Authority, Revenue Bonds, Widener University,		7/13 at 100.00		BBB+		499,395
		Series 2003, 5.250%, 7/15/24
1,000		Philadelphia Authority for Industrial Development, Pennsylvania, Airport Revenue Bonds, Philadelphia		7/11 at 101.00		A+		1,000,890
		Airport System Project, Series 2001A, 5.500%, 7/01/17 – FGIC Insured (Alternative Minimum Tax)
3,935		Total Pennsylvania						4,368,082
		South Carolina – 5.0%
1,500		Lexington County Health Service District, South Carolina, Hospital Revenue Refunding and		11/13 at 100.00		A+ (4)		1,664,205
		Improvement Bonds, Series 2003, 6.000%, 11/01/18 (Pre-refunded 11/01/13)
1,500		Medical University Hospital Authority, South Carolina, FHA-Insured Mortgage Revenue Bonds,		8/14 at 100.00		AA		1,559,070
		Series 2004A, 5.250%, 8/15/20 – MBIA Insured
520		South Carolina JOBS Economic Development Authority, Economic Development Revenue Bonds, Bon		11/12 at 100.00		A– (4)		567,304
		Secours Health System Inc., Series 2002A, 5.625%, 11/15/30 (Pre-refunded 11/15/12)
1,980		South Carolina JOBS Economic Development Authority, Economic Development Revenue Bonds, Bon		11/12 at 100.00		A–		1,994,711
		Secours Health System Inc., Series 2002B, 5.625%, 11/15/30
3,010		Tobacco Settlement Revenue Management Authority, South Carolina, Tobacco Settlement		5/11 at 101.00		BBB		3,281,352
		Asset-Backed Bonds, Series 2001B, 6.375%, 5/15/28
8,510		Total South Carolina						9,066,642
		South Dakota – 1.1%
1,010		South Dakota Health and Educational Facilities Authority, Revenue Bonds, Avera Health, Series		7/12 at 101.00		AA		1,013,363
		2002, 5.125%, 7/01/27 – AMBAC Insured
1,000		South Dakota Health and Educational Facilities Authority, Revenue Bonds, Sioux Valley		11/14 at 100.00		AA–		987,280
		Hospitals, Series 2004A, 5.250%, 11/01/34
2,010		Total South Dakota						2,000,643
		Tennessee – 1.2%
2,000		Knox County Health, Educational and Housing Facilities Board, Tennessee, Hospital Revenue		4/12 at 101.00		Ba2		2,093,740
		Bonds, Baptist Health System of East Tennessee Inc., Series 2002, 6.375%, 4/15/22
		Texas – 10.0%
1,500		Central Texas Regional Mobility Authority, Travis and Williamson Counties, Toll Road Revenue		1/15 at 100.00		BBB–		1,296,585
		Bonds, Series 2005, 5.000%, 1/01/45 – FGIC Insured
2,500		Harris County Health Facilities Development Corporation, Texas, Thermal Utility Revenue Bonds,		11/13 at 100.00		AA		2,476,600
		TECO Project, Series 2003, 5.000%, 11/15/30 – MBIA Insured
4,005		Harris County-Houston Sports Authority, Texas, Senior Lien Revenue Refunding Bonds, Series		11/30 at 61.17		AA		622,177
		2001A, 0.000%, 11/15/38 – MBIA Insured
3,000		Houston, Texas, Subordinate Lien Airport System Revenue Bonds, Series 2002B, 5.500%, 7/01/18 –		7/12 at 100.00		AAA		3,156,420
		FSA Insured
3,125		Katy Independent School District, Harris, Fort Bend and Waller Counties, Texas, General		2/12 at 100.00		AAA		3,312,125
		Obligation Bonds, Series 2002A, 5.000%, 2/15/32 (Pre-refunded 2/15/12)
4,750		Sam Rayburn Municipal Power Agency, Texas, Power Supply System Revenue Refunding Bonds, Series		10/12 at 100.00		A		4,943,752
		2002A, 5.500%, 10/01/17 – RAAI Insured
1,750		Texas, General Obligation Bonds, Water Financial Assistance Program, Series 2003A, 5.125%,		8/13 at 100.00		Aa1		1,663,025
		8/01/42 (Alternative Minimum Tax)
500		Victoria, Texas, General Obligation Bonds, Series 2001, 5.000%, 8/15/23 – FGIC Insured		8/11 at 100.00		AA–		507,915
21,130		Total Texas						17,978,599
		Washington – 0.3%
510		Port of Seattle, Washington, Revenue Bonds, Series 2001A, 5.000%, 4/01/31 – FGIC Insured		10/11 at 100.00		Aa2		512,698
		Wisconsin – 1.4%
2,500		Wisconsin, General Obligation Refunding Bonds, Series 2003-3, 5.000%, 11/01/26		11/13 at 100.00		AA–		2,544,325
$       177,490		Total Municipal Bonds (cost $174,599,213)						176,518,113
Shares		Description (1)						Value
		Common Stocks – 0.0%
		Airlines – 0.0%
220		UAL Corporation					$	1,148
		Total Common Stocks (cost $0)						1,148
		Total Investments (cost $174,599,213) – 98.1%						176,519,261
		Other Assets Less Liabilities – 1.9%						3,499,841
		Net Assets – 100%					$	180,019,102

---

(1)		All percentages shown in the Portfolio of Investments are based on net assets.
(2)		Optional Call Provisions: Dates (month and year) and prices of the earliest optional call or redemption. There
		may be other call provisions at varying prices at later dates. Certain mortgage-backed securities may be
		subject to periodic principal paydowns.
(3)		Ratings: Using the higher of Standard & Poor’s Group (“Standard & Poor’s”) or Moody’s Investor Service, Inc.
		(“Moody’s”) rating. Ratings below BBB by Standard & Poor’s or Baa by Moody’s are considered to be below
		investment grade.
		The Portfolio of Investments may reflect the ratings on certain bonds insured by ACA, AMBAC, CIFG, FGIC,
		MBIA, RAAI and XLCA as of June 30, 2008. Subsequent to June 30, 2008, and during the period this
		Portfolio of Investments was prepared, there may have been reductions to the ratings of certain bonds
		resulting from changes to the ratings of the underlying insurers both during the period and after period
		end. Such reductions would likely reduce the effective rating of many of the bonds insured by that insurer
		or insurers presented at period end.
(4)		Backed by an escrow or trust containing sufficient U.S. Government or U.S. Government agency securities
		which ensure the timely payment of principal and interest. Such investments are normally considered to be
		equivalent to AAA rated securities.
(5)		On December 9, 2002, UAL Corporation (“UAL”), the holding company of United Air Lines, Inc. (“United”)
		filed for federal bankruptcy protection. The Adviser determined that it was likely that United would not
		remain current on their interest payment obligations with respect to the bonds previously held and thus
		the Fund had stopped accruing interest on its UAL bonds. On February 1, 2006, UAL emerged from federal
		bankruptcy with the acceptance of its reorganization plan by the bankruptcy court. Under the settlement
		agreement established to meet UAL’s unsecured bond obligations, the bondholders, including the Fund,
		received three distributions of UAL common stock over the subsequent months, and the bankruptcy court
		dismissed all unsecured claims of bondholders, including those of the Fund. On May 5, 2006, the Fund
		liquidated such UAL common stock holdings. On September 29, 2006 and May 30, 2007, the Fund received
		additional distributions of 532 and 172 shares, respectively, of UAL common stock as a result of its earlier
		ownership of the UAL bonds. The Fund liquidated 532 shares of such UAL common stock holdings on
		November 15, 2006. The Fund received an additional distribution of 48 shares on November 14, 2007. The
		remaining 220 shares of UAL common stock were still held by the Fund at June 30, 2008.
N/R		Not rated.
(ETM)		Escrowed to maturity.
(IF)		Inverse floating rate investment.

Fair Value Measurements

During the current fiscal period, the Fund adopted the provisions of Statement of Financial Accounting Standards No. 157, Fair Value Measurements (SFAS 157). SFAS 157 defines fair value, establishes a framework for measuring fair value in generally accepted accounting principles, and expands disclosure about fair value measurements. In determining the value of the Fund’s investments various inputs are used. These inputs are summarized in the three broad levels listed below:

Level 1 – Quoted prices in active markets for identical securities.

Level 2 – Other significant observable inputs (including quoted prices for similar securities, interest

rates, prepayment speeds, credit risk, etc.).

Level 3 – Significant unobservable inputs (including management’s assumptions in determining the

fair value of investments).

The inputs or methodology used for valuing securities are not an indication of the risk associated with investing in those securities.

The following is a summary of the Fund’s fair value measurements as of June 30, 2008:

		Level 1		Level 2		Level 3		Total
Investments		$1,148		$176,518,113		$—		$176,519,261

Income Tax Information

The following information is presented on an income tax basis. Differences between amounts for financial statement and federal income tax purposes are primarily due to timing differences in recognizing taxable market discount, timing differences in recognizing certain gains and losses on investment transactions and the treatment of investments in inverse floating rate transactions subject to SFAS No. 140. To the extent that differences arise that are permanent in nature, such amounts are reclassified within the capital accounts on the Statement of Assets and Liabilities presented in the annual report, based on their federal tax basis treatment; temporary differences do not require reclassification. Temporary and permanent differences do not impact the net asset value of the Fund.

At June 30, 2008, the cost of investments was $174,535,683.

Gross unrealized appreciation and gross unrealized depreciation of investments at June 30, 2008, were as follows:

Gross unrealized:
Appreciation		$ 5,713,852
Depreciation		(3,730,274)
Net unrealized appreciation (depreciation) of investments		$ 1,983,578

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Item 2. Controls and Procedures.

1. The registrant's principal executive and principal financial officers, or persons performing similar functions, have concluded that the registrant's disclosure controls and procedures (as defined in Rule 30a-3(c) under the Investment Company Act of 1940, as amended (the "1940 Act") (17 CFR 270.30a-3(c))) are effective, as of a date within 90 days of the filing date of this report that includes the disclosure required by this paragraph, based on their evaluation of the controls and procedures required by Rule 30a-3(b) under the 1940 Act (17 CFR 270.30a-3(b)) and Rule 13a-15(b) or 15d-15(b) under the Securities Exchange Act of 1934 (17 CFR 240.13a-15(b) or 240.15d-15(b)).
2. There were no changes in the registrant's internal control over financial reporting (as defined in Rule 30a-3(d) under the 1940 Act (17 CFR 270.30a-3(d)) that occurred during the registrant's last fiscal quarter that have materially affected, or are reasonably likely to materially affect, the registrant's internal control over financial reporting.

Item 3. Exhibits.

File as exhibits as part of this Form a separate certification for each principal executive officer and principal financial officer of the registrant as required by Rule 30a-2(a) under the 1940 Act (17 CFR 270.30a-2(a)), exactly as set forth below: See EX-99 CERT attached hereto.

SIGNATURES

Pursuant to the requirements of the Securities Exchange Act of 1934 and the Investment Company Act of 1940, the registrant has duly caused this report to be signed on its behalf by the undersigned, thereunto duly authorized.

(Registrant)         Nuveen Select Tax-Free Income Portfolio 3         

By (Signature and Title)          /s/ Kevin J. McCarthy                    
                                                  Kevin J. McCarthy
                                                  Vice President and Secretary

Date         August 29, 2008        

Pursuant to the requirements of the Securities Exchange Act of 1934 and the Investment Company Act of 1940, this report has been signed below by the following persons on behalf of the registrant and in the capacities and on the dates indicated.

By (Signature and Title)         /s/ Gifford R. Zimmerman                    
                                                 Gifford R. Zimmerman
                                                 Chief Administrative Officer (principal executive officer) 

Date         August 29, 2008        

By (Signature and Title)         /s/ Stephen D. Foy                              
                                                 Stephen D. Foy
                                                 Vice President and Controller (principal financial officer) 

Date        August 29, 2008