Form N-Q

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)


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


Jessica R. Droeger—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:            03/31          

Date of reporting period:          06/30/05         

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, 2005             
 
 
 
Principal        Optional Call        Market 
Amount (000)    Description    Provisions*    Ratings**    Value 
 
    Alabama - 0.3%             
$ 500    Marshall County Healthcare Authority, Alabama, Revenue Bonds, Series 2002A, 6.250%, 1/01/22    1/12 at 101.00    A-    $ 556,335 
 
    Arizona - 0.4%             
700    Tucson, Arizona, Junior Lien Street and Highway User Revenue Bonds, Series 2001, 5.000%, 7/01/17 -    7/11 at 100.00    AAA    773,752 
    AMBAC Insured             
 
    California - 6.3%             
2,105    Azusa Unified School District, Los Angeles County, California, General Obligation Bonds, Series    7/12 at 100.00    AAA    2,319,394 
    2002, 5.375%, 7/01/21 - FSA Insured             
3,350    California Department of Water Resources, Power Supply Revenue Bonds, Series 2002A, 6.000%,    5/12 at 101.00    A2    3,901,075 
    5/01/14             
3,000    Golden State Tobacco Securitization Corporation, California, Tobacco Settlement Asset-Backed Bonds,    6/13 at 100.00    BBB    3,379,380 
    Series 2003A-1, 6.750%, 6/01/39             
2,000    Golden State Tobacco Securitization Corporation, California, Enhanced Tobacco Settlement    No Opt. Call    A-    2,004,900 
    Asset-Backed Bonds, Series 2003B, 5.250%, 6/01/16             
250    Santa Ana Unified School District, Orange County, California, General Obligation Bonds, Series    8/10 at 101.00    AAA    277,015 
    2000, 5.700%, 8/01/29 - FGIC Insured             
 
    Colorado - 5.9%             
    Colorado Health Facilities Authority, Revenue Bonds, Catholic Health Initiatives, Series 2002A:             
2,265    5.500%, 3/01/22    3/12 at 100.00    AA***    2,542,508 
1,735    5.500%, 3/01/22    3/12 at 100.00    AA    1,911,519 
2,700    Denver City and County, Colorado, Airport System Revenue Bonds, Series 1991D, 7.750%, 11/15/13    No Opt. Call    A    3,197,907 
    (Alternative Minimum Tax)             
3,000    Denver Convention Center Hotel Authority, Colorado, Senior Revenue Bonds, Convention Center Hotel,    12/13 at 100.00    AAA    3,176,250 
    Series 2003A, 5.000%, 12/01/24 - XLCA Insured             
325    E-470 Public Highway Authority, Colorado, Senior Revenue Bonds, Series 1997A, 5.000%, 9/01/26 -    9/07 at 101.00    AAA    339,232 
    MBIA Insured             
 
    Connecticut - 0.1%             
250    Connecticut Health and Educational Facilities Authority, Revenue Bonds, Bridgeport Hospital Issue,    7/05 at 100.00    AAA    250,748 
    Series 1992A, 6.625%, 7/01/18 - MBIA Insured             
 
    District of Columbia - 0.2%             
235    District of Columbia, General Obligation Refunding Bonds, Series 1994A-1, 6.500%, 6/01/10 - MBIA    No Opt. Call    AAA    270,034 
    Insured             
15    District of Columbia, General Obligation Bonds, Series 1993E, 6.000%, 6/01/13 - MBIA Insured    12/05 at 100.00    AAA    15,016 
 
    Florida - 5.0%             
4,000    JEA, Florida, Subordinate Lien Electric System Revenue Bonds, Series 2002D, 4.625%, 10/01/22    10/07 at 100.00    Aa3    4,029,520 
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    5,440,776 
    5.000%, 10/01/18             
 
    Georgia - 0.6%             
1,525    Atlanta, Georgia, Airport Facilities Revenue Bonds, Series 1990, 0.000%, 1/01/10 (Alternative    No Opt. Call    AAA    1,205,131 
    Minimum Tax) - MBIA Insured             
 
    Illinois - 19.2%             
1,160    Chicago Metropolitan Housing Development Corporation, Illinois, FHA-Insured Section 8 Assisted    7/05 at 100.00    AA    1,178,954 
    Housing Development Revenue Refunding Bonds, Series 1992, 6.850%, 7/01/22             
700    Chicago, Illinois, Special Facility Revenue Refunding Bonds, O'Hare International Airport, United    No Opt. Call    N/R    115,745 
    Air Lines Inc. Project, Series 2001C, 6.300%, 5/01/16 #             
1,930    Illinois Development Finance Authority, Revenue Bonds, Midwestern University, Series 2001B,    5/11 at 101.00    A-    2,098,798 
    5.750%, 5/15/16             
2,185    Illinois Finance Authority, Revenue Bonds, YMCA of Southwest Illinois, Series 2005, 5.000%,    9/15 at 100.00    AA    2,262,393 
    9/01/31 - RAAI Insured             
1,500    Illinois Health Facilities Authority, Revenue Bonds, Evangelical Hospitals Corporation, Series    No Opt. Call    N/R***    1,883,325 
    1992C, 6.250%, 4/15/22             
4,000    Illinois Health Facilities Authority, Revenue Bonds, Franciscan Sisters Healthcare Corporation,    9/06 at 100.00    AAA    4,183,040 
    Series 1992B, 6.625%, 9/01/13 (Pre-refunded to 9/01/06) - MBIA Insured             
4,465    Illinois Health Facilities Authority, Remarketed Revenue Bonds, University of Chicago Project,    8/11 at 103.00    Aa1    4,945,434 
    Series 1985A, 5.500%, 8/01/20             
2,225    Illinois Health Facilities Authority, Revenue Refunding Bonds, Elmhurst Memorial Healthcare, Series    1/13 at 100.00    A2    2,521,303 
    2002, 6.250%, 1/01/17             
5,700    Illinois, Sales Tax Revenue Bonds, First Series 2002, 5.000%, 6/15/22    6/13 at 100.00    AAA    6,120,888 
2,000    Illinois, Sales Tax Revenue Bonds, Series 1997X, 5.600%, 6/15/17    6/07 at 101.00    AAA    2,114,940 
6,000    Metropolitan Pier and Exposition Authority, Illinois, Revenue Refunding Bonds, McCormick Place    6/12 at 101.00    AAA    6,467,400 
    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    AAA    1,420,575 
1,000    Yorkville, Illinois, General Obligation Debt Certificates, Series 2003, 5.000%, 12/15/22 - RAAI    12/11 at 100.00    AA    1,036,810 
    Insured             
 
    Indiana - 3.7%             
1,000    Franklin Community Multi-School Building Corporation, Marion County, Indiana, First Mortgage    7/14 at 100.00    AAA    1,070,140 
    Revenue Bonds, Series 2004, 5.000%, 7/15/22 - FGIC Insured             
3,500    Indiana Health Facility Financing Authority, Hospital Revenue Bonds, Methodist Hospitals Inc.,    9/11 at 100.00    A+    3,672,725 
    Series 2001, 5.375%, 9/15/22             
2,000    Indianapolis Local Public Improvement Bond Bank, Indiana, Waterworks Project, Series 2002A,    7/12 at 100.00    AAA    2,166,360 
    5.250%, 7/01/33 - MBIA Insured             
 
    Iowa - 3.6%             
    Iowa Tobacco Settlement Authority, Tobacco Settlement Asset-Backed Revenue Bonds, Series 2001B:             
3,850    5.300%, 6/01/25    6/11 at 101.00    BBB    3,927,963 
2,850    5.600%, 6/01/35    6/11 at 101.00    BBB    2,915,408 
 
    Massachusetts - 0.8%             
1,000    Massachusetts Development Finance Agency, Resource Recovery Revenue Bonds, Ogden Haverhill    12/08 at 102.00    BBB    1,013,140 
    Associates, Series 1998B, 5.200%, 12/01/13 (Alternative Minimum Tax)             
500    Massachusetts Health and Educational Facilities Authority, Revenue Bonds, Partners HealthCare    7/11 at 101.00    AA-    566,130 
    System Inc., Series 2001C, 6.000%, 7/01/17             
 
    Michigan - 5.1%             
400    East Lansing School District, Ingham County, Michigan, General Obligation Bonds, Series 2000,    5/10 at 100.00    AA***    445,244 
    5.625%, 5/01/30 (Pre-refunded to 5/01/10)             
4,000    Michigan Housing Development Authority, Single Family Mortgage Revenue Bonds, Series 1996C,    6/06 at 102.00    AA+    4,135,360 
    5.950%, 12/01/17             
235    Michigan State Hospital Finance Authority, Revenue Refunding Bonds, Detroit Medical Center    8/05 at 100.00    BB-    235,085 
    Obligated Group, Series 1993A, 6.500%, 8/15/18             
2,900    Michigan State Hospital Finance Authority, Hospital Revenue Refunding Bonds, Trinity Health Credit    12/12 at 100.00    AA-    3,093,285 
    Group, Series 2002C, 5.375%, 12/01/30             
1,600    Plymouth-Canton Community School District, Wayne and Washtenaw Counties, Michigan, Unlimited Tax    5/09 at 100.00    AA    1,667,936 
    General Obligation School Building and Site Bonds, Series 1999, 4.750%, 5/01/18             
 
    Mississippi - 0.4%             
725    Mississippi Hospital Equipment and Facilities Authority, Revenue Bonds, Baptist Memorial    9/14 at 100.00    N/R    756,095 
    Healthcare, Series 2004B-1, 5.000%, 9/01/24             
 
    Nebraska - 2.0%             
3,500    Nebraska Public Power District, General Revenue Bonds, Series 2002B, 5.000%, 1/01/33 - AMBAC    1/13 at 100.00    AAA    3,691,275 
    Insured             
 
    Nevada - 4.9%             
4,000    Director of Nevada State Department of Business and Industry, Revenue Bonds, Las Vegas Monorail    1/10 at 100.00    AAA    4,263,600 
    Project, First Tier, Series 2000, 5.375%, 1/01/40 - AMBAC Insured             
4,510    Reno, Nevada, Capital Improvement Revenue Bonds, Series 2002, 5.500%, 6/01/22 - FGIC Insured    6/12 at 100.00    AAA    5,001,455 
 
    New Hampshire - 0.4%             
775    New Hampshire Housing Finance Agency, Single Family Mortgage Acquisition Bonds, Series 2001A,    5/11 at 100.00    Aa2    782,820 
    5.600%, 7/01/21 (Alternative Minimum Tax)             
 
    New Mexico - 2.2%             
4,000    University of New Mexico, FHA-Insured Mortgage Hospital Revenue Bonds, Series 2004, 4.625%,    7/14 at 100.00    AAA    4,069,280 
    1/01/25 - FSA Insured             
 
    New York - 3.5%             
2,335    Long Island Power Authority, New York, Electric System General Revenue Bonds, Series 2001A,    9/11 at 100.00    A-    2,549,516 
    5.375%, 9/01/21             
35    New York City, New York, General Obligation Bonds, Series 1991B, 7.000%, 2/01/18    8/05 at 100.00    A+    35,110 
1,835    Dormitory Authority of the State of New York, Second General Resolution Consolidated Revenue Bonds,    No Opt. Call    A2    2,030,042 
    City University System, Series 1990C, 7.500%, 7/01/10             
1,850    New York State Tobacco Settlement Financing Corporation, Tobacco Settlement Asset-Backed and State    6/10 at 100.00    AA-    2,033,816 
    Contingency Contract-Backed Bonds, Series 2003B-1C, 5.500%, 6/01/15             
 
    North Carolina - 4.3%             
5,000    North Carolina Municipal Power Agency 1, Catawba Electric Revenue Bonds, Series 2003A, 5.250%,    1/13 at 100.00    AAA    5,496,800 
    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    2,579,805 
    7/01/16 - FSA Insured             
 
    Oklahoma - 1.7%             
3,000    Oklahoma Development Finance Authority, Revenue Bonds, St. John Health System, Series 2004,    2/14 at 100.00    AA    3,128,970 
    5.000%, 2/15/24             
 
    Pennsylvania - 2.5%             
2,435    Dauphin County Industrial Development Authority, Pennsylvania, Water Development Revenue Refunding    No Opt. Call    A-    3,049,424 
    Bonds, Dauphin Consolidated Water Supply Company, Series 1992B, 6.700%, 6/01/17             
500    Pennsylvania Higher Educational Facilities Authority, Revenue Bonds, Widener University, Series    7/13 at 100.00    BBB+    527,300 
    2003, 5.250%, 7/15/24             
1,000    Philadelphia Authority for Industrial Development, Pennsylvania, Airport Revenue Bonds,    7/11 at 101.00    AAA    1,100,440 
    Philadelphia Airport System Project, Series 2001A, 5.500%, 7/01/17 (Alternative Minimum Tax) -             
    FGIC Insured             
 
    South Carolina - 3.2%             
1,500    Lexington County Health Service District, South Carolina, Hospital Revenue Refunding and    11/13 at 100.00    A    1,693,440 
    Improvement Bonds, Series 2003, 6.000%, 11/01/18             
1,500    Medical University Hospital Authority, South Carolina, FHA-Insured Mortgage Revenue Bonds, Series    8/14 at 100.00    AAA    1,648,110 
    2004A, 5.250%, 8/15/20 - MBIA Insured             
2,500    South Carolina JOBS Economic Development Authority, Economic Development Revenue Bonds, Bon Secours    11/12 at 100.00    A-    2,670,825 
    Health System Inc., Series 2002A, 5.625%, 11/15/30             
 
    South Dakota - 1.1%             
1,010    South Dakota Health and Educational Facilities Authority, Revenue Bonds, Avera Health, Series 2002,    7/12 at 101.00    AAA    1,074,983 
    5.125%, 7/01/27 - AMBAC Insured             
1,000    South Dakota Health and Educational Facilities Authority, Revenue Bonds, Sioux Valley Hospital and    11/14 at 100.00    A+    1,060,430 
    Health System, Series 2004A, 5.250%, 11/01/34             
 
    Tennessee - 1.1%             
2,000    Knox County Health, Educational and Housing Facilities Board, Tennessee, Hospital Revenue Bonds,    4/12 at 101.00    Baa3    2,136,880 
    Baptist Health System of East Tennessee Inc., Series 2002, 6.375%, 4/15/22             
 
    Texas - 15.5%             
1,500    Central Texas Regional Mobility Authority, Travis and Williamson Counties, Toll Road Revenue Bonds,    1/15 at 100.00    AAA    1,571,070 
    Series 2005, 5.000%, 1/01/45 - FGIC Insured             
3,755    Grand Prairie Industrial Development Authority, Texas, Industrial Development Revenue Refunding    No Opt. Call    A-    3,765,927 
    Bonds, Baxter International Inc. Project, Series 1992, 6.550%, 12/01/12             
2,500    Harris County Health Facilities Development Corporation, Texas, Thermal Utility Revenue Bonds, TECO    11/13 at 100.00    AAA    2,632,650 
    Project, Series 2003, 5.000%, 11/15/30 - MBIA Insured             
3,000    Houston, Texas, Subordinate Lien Airport System Revenue Bonds, Series 2002B, 5.500%, 7/01/18 - FSA    7/12 at 100.00    AAA    3,353,010 
    Insured             
3,125    Katy Independent School District, Harris, Fort Bend and Waller Counties, Texas, General Obligation    2/12 at 100.00    AAA    3,265,375 
    Bonds, Series 2002A, 5.000%, 2/15/32             
    Killeen Independent School District, Bell County, Texas, General Obligation Bonds, Series 1998:             
1,425    5.000%, 2/15/14 (Pre-refunded to 2/15/08)    2/08 at 100.00    AAA    1,503,019 
400    5.000%, 2/15/14    2/08 at 100.00    AAA    419,624 
5,000    North Central Texas Health Facilities Development Corporation, Hospital Revenue Refunding Bonds,    5/06 at 102.00    AA-    5,148,250 
    Baylor Healthcare System, Series 1995, 5.250%, 5/15/16             
4,750    Sam Rayburn Municipal Power Agency, Texas, Power Supply System Revenue Refunding Bonds, Series    10/12 at 100.00    AA    5,185,053 
    2002A, 5.500%, 10/01/17 - RAAI Insured             
1,750    Texas, General Obligation Bonds, Water Financial Assistance Program, Series 2003A, 5.125%, 8/01/42    8/13 at 100.00    Aa1    1,823,868 
    (Alternative Minimum Tax)             
500    Victoria, Texas, General Obligation Bonds, Series 2001, 5.000%, 8/15/23 - FGIC Insured    8/11 at 100.00    AAA    532,575 
 
    Utah - 0.9%             
1,710    Intermountain Power Agency, Utah, Power Supply Revenue Refunding Bonds, Series 1996D, 5.000%,    7/06 at 102.00    A+    1,759,402 
    7/01/21             
 
    Washington - 2.1%             
3,880    Washington, General Obligation Bonds, Series 1993A, 4.500%, 10/01/18    10/05 at 100.00    Aa1    3,881,472 
 
    Wisconsin - 1.4%             
2,500    Wisconsin, General Obligation Refunding Bonds, Series 2003-3, 5.000%, 11/01/26    11/13 at 100.00    AA-    2,658,300 

$ 174,125        Total Long-Term Investments (cost $175,219,246) - 98.4%    185,728,884 
 
        Other Assets Less Liabilities - 1.6%    3,014,326 
 
        Net Assets - 100%    $188,743,210 
 
 
 
    *    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.     
    **    Ratings: Using the higher of Standard & Poor's or Moody's rating.     
    ***    Securities are backed by an escrow or trust containing sufficient U.S. Government or U.S. Government agency     
        securities which ensures the timely payment of principal and interest. Such securities are normally considered     
        to be equivalent to AAA rated securities.     
    #    On December 9 2002, UAL Corporation, the holdong company of United Air Lines, Inc filed for federal bankruptcy     
        protection. The Adviser determined that it was likely United would not remain current on their interest payment     
        obligations with respect to these bonds and thus has stopped accruing interest.     
    N/R    Investment is not rated.     
 
        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 income on taxable market     
        discount securities and timing differences in recognizing certain gains and losses on investment transactions.     
 
        At June 30, 2005, the cost of investments was $175,171,271.     
 
        Gross unrealized appreciation and gross unrealized depreciation of investments at June 30, 2005, were as     
        follows:     
 
        Gross unrealized:     
           Appreciation    $11,142,299 
           Depreciation    (584,686) 
 
        Net unrealized appreciation of investments    $10,557,613 

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: 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/ Jessica R. Droeger--Vice President and Secretary        

Date         08/26/05        

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--Chief Administrative Officer (principal executive officer)        

Date         08/26/05        

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

Date         08/26/05        

* Print the name and title of each signing officer under his or her signature.