OMB APPROVAL OMB Number: 3235-0578 Expires: April 30, 2010 Estimated average burden hours per response..... 10.5 UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 FORM N-Q CERTIFIED SHAREHOLDER REPORT OF REGISTERED MANAGEMENT INVESTMENT COMPANIES Investment Company Act file number 811-21321 Pioneer Municipal High Income Trust (Exact name of registrant as specified in charter) 60 State Street, Boston, MA 02109 (Address of principal executive offices) (ZIP code) Dorothy E. Bourassa, Pioneer Investment Management, Inc., 60 State Street, Boston, MA 02109 (Name and address of agent for service) Registrant's telephone number, including area code: (617) 742-7825 Date of fiscal year end: April 30 Date of reporting period: January 31, 2009 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 close of the first and third fiscal quarters, pursuant to Rule 30b1-5under the Investment Company Act of 1940 (17 CFR 270.30b-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 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. ss. 3507. ITEM 1. Schedule of Investments. Pioneer Municipal High Income Trust SCHEDULE OF INVESTMENTS 1/31/09 (unaudited) Principal Amount Value ($) TAX EXEMPT OBLIGATIONS - 133.4% of Net Assets Alabama - 0.7% 1,000,000 Huntsville-Redstone Village Special Care Facilities F 629,300 2,000,000 Huntsville-Redstone Village Special Care Facilities F 1,054,120 1,683,420 Arizona - 2.3% 5,000,000 Apache County Industrial Development Authority, 5.85% 4,275,200 970,000 Pima County Industrial Development Authority, 7.25%, 789,716 500,000 Yavapai County Industrial Development Authority, 6.0% 377,405 5,442,321 California - 12.1% 7,885,000 (a) California State University Revenue, RIB, 9.142%, 11/ 6,865,864 4,500,000 California Statewide Communities Development Authority Environmental Facilities Revenue, 9.0%, 12/1/38 3,576,780 1,000,000 California Statewide Communities Development Authorit 731,360 5,150,000 + Golden State Tobacco Securitization Corp., 7.8%, 6/1/ 6,355,048 7,000,000 + Golden State Tobacco Securitization Corp., 7.875%, 6/ 8,658,580 2,500,000 University of California Revenue, 5.0%, 5/15/25 2,528,675 655,000 Valley Health System Hospital Revenue, 6.5%, 5/15/25 399,353 29,115,660 Connecticut - 5.7% 10,335,000(a) Connecticut Health & Educational Facilities Authority10,283,532 5,000,000 Mohegan Tribe Indians Gaming Authority, 6.25%, 1/1/31 3,467,200 13,750,732 Delaware - 0.4% 765,000 Sussex County Delaware Revenue, 5.9%, 1/1/26 522,235 600,000 Sussex County Delaware Revenue, 6.0%, 1/1/35 363,366 885,601 District of Columbia - 3.2% 5,000,000 District of Columbia Tobacco Settlement Financing Cor 3,415,900 6,000,000 District of Columbia Tobacco Settlement Financing Cor 4,144,980 7,560,880 Florida - 4.3% 1,800,000 Beacon Lakes Community Development, 6.9%, 5/1/35 1,256,382 2,000,000 Brevard County Health Facilities Authority Revenue, 5 1,373,300 2,500,000 Liberty County Subordinate Revenue, 8.25%, 7/1/28 2,029,500 1,000,000 St. Johns County Industrial Development Authority Rev 613,200 2,000,000 St. Johns County Industrial Development Authority Rev 1,078,960 5,000,000 Tallahassee Health Facilities Revenue, 6.375%, 12/1/3 4,070,300 10,421,642 Georgia - 3.7% 4,240,000 (a) Atlanta Georgia Water & Waste Revenue, RIB, 8.622%, 1 3,049,238 2,400,000 Fulton County Residential Care Facilities Revenue, 5. 1,427,472 2,600,000 Fulton County Residential Care Facilities Revenue, 5. 1,326,494 7,500,000 (b) Main Street Natural Gas Project Revenue, 6.25%, 7/15/ 1,481,175 4,500,000 (b) Main Street Natural Gas Project Revenue, 6.375%, 7/15 888,705 1,000,000 Rockdale County Development Authority Revenue, 6.125% 644,860 8,817,944 Guam - 1.5% 5,000,000 Northern Mariana Islands, 5.0%, 10/1/22 3,508,700 Idaho - 1.6% 5,000,000 Power County Industrial Development Corp., 6.45%, 8/1 3,893,900 Illinois - 7.8% 2,000,000 (c) Centerpoint Intermodal Center, 10.0%, 6/15/23 (144A) 1,537,900 1,000,000 Illinois Finance Authority Revenue, 6.0%, 11/15/27 678,860 4,000,000 Illinois Finance Authority Revenue, 6.0%, 11/15/39 2,297,720 1,500,000 (b) Illinois Health Facilities Authority Revenue, 6.9%, 1 814,050 16,880,000(d) Metropolitan Pier & Exposition Authority Dedicated St12,132,838 1,800,000 Southwestern Illinois Development Authority Revenue, 1,151,478 18,612,846 Indiana - 3.4% 5,000,000 Indiana Health & Educational Facility Financing Autho 3,449,400 1,000,000 Indiana State Development Finance Authority Revenue, 727,050 4,300,000 Indiana State Development Finance Authority Revenue, 4,068,015 8,244,465 Louisiana - 2.0% 1,500,000 Louisiana Local Government Environmental Facilities R 1,041,780 5,000,000 Louisiana Public Facilities Authority Revenue, 5.5%, 3,660,700 4,702,480 Massachusetts - 4.2% 2,440,000 Massachusetts Development Finance Agency Revenue, 7.1 1,830,171 3,500,000 Massachusetts Health & Educational Facilities Authori 2,980,845 2,500,000 Massachusetts Health & Educational Facilities Authori 1,665,075 5,000,000 Massachusetts Health & Educational Facilities Authori 3,541,000 10,017,091 Michigan - 2.2% 950,000 Doctor Charles Drew Academy, 5.7%, 11/1/36 515,195 1,700,000 Flint Michigan Hospital Building Authority Revenue, 5 1,369,282 1,500,000 John Tolfree Health System Corp., 6.0%, 9/15/23 1,107,435 2,000,000 Michigan State Hospital Finance Authority Revenue, 5. 1,299,660 1,470,000 Star International Academy Certificates of Participat 923,968 5,215,540 Minnesota - 0.6% 1,675,000 Duluth Economic Development Authority Health Care Fac 1,317,538 Mississippi - 1.0% 3,000,000 Mississippi Business Finance Corp. Pollution Control 2,437,710 Montana - 0.3% 1,600,000 Two Rivers Authority, Inc. Correctional Facility Impr 640,576 Nebraska - 0.6% 2,000,000 Grand Island Solid Waste Disposal Facilities Revenue, 1,513,100 Nevada - 0.1% 2,000,000 Nevada State Department of Business & Industry, 7.25% 299,760 New Jersey - 11.1% 2,000,000 New Jersey Economic Development Authority Revenue, 6. 1,428,700 13,350,000 New Jersey Economic Development Authority Revenue, 6. 8,343,483 1,000,000 New Jersey Economic Development Authority Revenue, 6. 672,250 6,150,000 New Jersey Economic Development Authority Revenue, 7. 4,007,586 10,000,000 + Tobacco Settlement Financing Corp., 6.75%, 6/1/39 12,083,400 26,535,419 New Mexico - 1.3% 1,500,000 Otero County New Mexico Project Revenue, 6.0%, 4/1/23 1,111,275 2,960,000 Otero County New Mexico Project Revenue, 6.0%, 4/1/28 2,078,956 3,190,231 New York - 11.1% 2,500,000 Albany New York Industrial Development Agency Civic F 1,858,600 3,000,000 Dutchess County Industrial Development Agency Revenue 2,676,990 2,000,000 Nassau County New York Industrial Development Agency 1,376,580 2,000,000 New York City Industrial Development Agency, 5.375%, 1,615,220 12,990,000 New York City Industrial Development Agency, 6.9%, 8/ 5,332,005 7,040,000 (a) New York State Dormitory Authority Revenue, RIB, 12.0 8,098,957 2,000,000 Suffolk County Industrial Development Agency, 7.25%, 1,542,480 4,000,000 Triborough Bridge & Tunnel Authority Revenue, 5.25%, 4,009,760 26,510,592 North Carolina - 2.4% 4,030,000 Charlotte North Carolina Special Facilities Revenue, 2,079,641 5,740,000 Charlotte North Carolina Special Facilities Revenue, 3,664,244 5,743,885 Oklahoma - 6.3% 3,000,000 + Oklahoma Development Finance Authority Revenue, 5.625 3,104,430 7,000,000 + Oklahoma Development Finance Authority Revenue, 5.625 7,243,670 1,225,000 Tulsa Municipal Airport Revenue, 6.25%, 6/1/20 837,165 4,350,000 Tulsa Municipal Airport Revenue, 7.35%, 12/1/11 3,880,635 15,065,900 Pennsylvania - 8.3% 3,000,000 Allegheny County Hospital Development Authority Reven 1,624,650 1,550,000 Allegheny County Hospital Development Authority Reven 1,275,588 12,300,000 + Allegheny County Hospital Development Authority Reven14,270,952 1,000,000 Columbia County Hospital Authority Health Care Revenu 625,120 925,000 Hazleton Health Services Authority Hospital Revenue, 723,905 1,280,000 Langhorne Manor Borough Higher Education & Health Aut 956,032 500,000 Pennsylvania Higher Educational Facilities Authority 370,285 19,846,532 Rhode Island - 1.7% 6,000,000 Central Falls Detention Facilities Revenue, 7.25%, 7/ 4,092,960 South Carolina - 2.9% 5,185,000 + South Carolina Jobs Economic Development Authority Re 6,133,336 665,000 + South Carolina Jobs Economic Development Authority Re 793,571 6,926,907 Tennessee - 5.5% 7,000,000 + Johnson City Health & Educational Facilities Board Ho 8,020,040 2,480,000 Knox County Health, Educational & Housing Facilities Board Hospital Revenue, 6.375%, 4/15/22 2,472,039 4,600,000 Sullivan County Health, Educational & Housing Facilities Board Hospital Revenue, 5.25%, 9/1/36 2,677,798 13,169,877 Texas - 15.2% 1,345,000 Bexar County Housing Finance Corp., 8.0%, 12/1/36 960,182 1,000,000 Dallas-Fort Worth International Airport Revenue, 6.0% 599,990 4,000,000 Decatur Hospital Authority Revenue, 7.0%, 9/1/25 3,120,240 2,000,000 Gulf Coast Industrial Development Authority Revenue, 1,284,080 3,750,000 Houston Airport System Special Facilities Revenue, 5. 2,106,375 5,340,000 Lubbock Health Facilities Development Corp., 6.625%, 3,637,875 10,000,000 North Texas Tollway Authority Revenue, 5.75%, 1/1/33 8,984,000 2,810,000 (a) Northside Independent School District, RIB, 10.555%, 2,833,773 500,000 Sabine River Authority Pollution Control Revenue, 6.1 264,740 7,040,000 (a) Texas State, RIB, 11.348%, 4/1/30 (144A) 7,085,971 735,000 (e) Willacy County Local Government Corp. Revenue, 6.0%, 738,175 1,075,000 Willacy County Local Government Corp. Revenue, 6.0%, 1,025,088 5,250,000 Willacy County Local Government Corp. Revenue, 6.875% 3,802,470 36,442,959 Utah - 0.2% 800,000 Spanish Fork City Charter School Revenue, 5.55%, 11/1 546,552 Vermont - 0.6% 1,500,000 Vermont Educational & Health Buildings Financing Agen 1,526,685 Virginia - 0.3% 1,000,000 Peninsula Ports Authority, 6.0%, 4/1/33 825,950 Washington - 8.7% 4,710,000 Spokane Public Facilities District Hotel/Motel Tax & 4,811,077 7,025,000 Tobacco Settlement Authority Revenue, 6.625%, 6/1/32 5,121,225 14,315,000 Washington State General Obligation, 0.0%, 6/1/22 7,776,767 5,000,000 Washington State Housing Finance Committee Nonprofit 3,253,900 20,962,969 Wisconsin - 0.1% 2,320,000 Aztalan Wisconsin Exempt Facilities Revenue, 7.5%, 5/ 348,000 TOTAL TAX-EXEMPT OBLIGATIONS (Cost $380,378,641) 319,817,324 MUNICIPAL COLLATERALIZED DEBT OBLIGATION - 3.6% of Net Assets 10,000,000(c)(Non-Profit Preferred Funding Trust I,12.0%, 9/15/37 ( 8,700,100 TOTAL MUNICIPAL COLLATERALIZED DEBT OBLIGATION (Cost $10,000,000) 8,700,100 Shares COMMON STOCK - 0.7% of Net Assets 247,994 (g) Delta Air Lines, Inc. 1,711,159 TOTAL COMMON STOCK (Cost $6,612,756) 1,711,159 TOTAL INVESTMENTS IN SECURITIES - 137.7% (Cost $396,991,397) (h)(i) 330,228,583 OTHER ASSETS AND LIABILITIES - 4.4% 10,514,545 PREFERRED SHARES AT REDEMPTION VALUE, INCLUDING DIVIDENDS PAYABLE - (42.1)% (101,007,570) NET ASSETS APPLICABLE TO COMMON SHAREOWNERS - 100.0% 239,735,558 RIB Residual Interest Bonds (144A) Security is exempt from registration under Rule 144A of the Securities Act of 1933. Such securities may be resold normally to qualified institutional buyers in a transaction exempt from registration. At January 31, 2009 the value of these securities amounted to $49,001,887 or 20.4% of net assets applicable to common shareowners. + Prerefunded bonds have been collateralized by U.S. Treasury securities or U.S. Government Agencies which are held in escrow to pay interest and principal on the tax exempt issue and to retire the bonds in full at the earliest refunding date. (a) The interest rate is subject to change periodically and inversely based upon prevailing market rates. The interest rate shown is the coupon rate at January 31, 2009. (b) Security is in default and is non-income producing. (c) The interest rate is subject to change periodically. The interest rate shown is the coupon rate at January 31, 2009. (d) Debt obligation initially issued at one coupon which converts to a higher coupon at a specific date. The rate shown is the coupon rate at January 31, 2009. (e) Escrow to maturity. (f) Indicates a security that has been deemed illiquid. The aggregate cost of illiquid securities is $10,000,000. The aggregate value $8,700,100 represents 3.6% of the net assets. (g) Non-income producing. (i) At January 31, 2009, the net unrealized loss on investments based on cost for federal income tax purposes of $394,959,276 was as follows: Aggregate gross unrealized gain for all investments $18,015,249 there is an excess of value over tax cost Aggregate gross unrealized loss for all investments (82,745,942) there is an excess of tax cost over value $(64,730,693) Net unrealized loss For financial reporting purposes net unrealized loss on investments was $66,762,814 and cost of investments aggregated $396,991,397. Various inputs are used in determining the value of the Fund's investments. These inputs are summarized in the three broad levels listed below. Highest priority is given to Level 1 inputs and lowest priority is given to Level 3. 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 the Fund's own assumptions in determining fair value of investments) The following is a summary of the inputs used as of January 31, 2009, in valuing the Fund's assets: Valuation Inputs Investments Other Financial in Securities Instruments Level 1 - Quoted Prices $1,711,159 $0 Level 2 - Other Significant Observable Inputs 328,517,424 (244,233) Level 3 - Significant Unobservable Inputs 0 0 Total $330,228,583 ($244,233) * Other financial instruments include foreign exchange contracts. ITEM 2. CONTROLS AND PROCEDURES. (a) Disclose the conclusions of the registrant's principal executive officer or officers and principal financial officer or officers, or persons performing similar functions, about the effectiveness of the registrant's disclosure controls and procedures (as defined in Rule 30a-3(c) under the Act (17 CFR 270.30a-3(c))) as of a date within 90 days of the filing date of the report that includes the disclosure required by this paragraph, based on their evaluation of these controls and procedures required by Rule 30a-3(b) under the Act (17 CFR270.30a-3(b))) and Rule 13a-15(b) or 15d-15(b) under the Exchange Act (17 CFR240.13a-15(b) or 240.15d-15(b)). The registrant's principal executive officer and principal financial officer have concluded that the registrant's disclosure controls and procedures are effective based on their evaluation of these controls and procedures as of a date within 90 days of the filing date of this report. (b) Disclose any change in the registrant's internal controls over financial reporting (as defined in Rule 30a-3(d) under the Act (17 CFR270.30a-3(d)) that occurred during the registrant's last fiscal quarter that has materially affected, or is reasonably likely to materially affect, the registrant's internal control over financial reporting. There were no significant changes in the registrant's internal control over financial reporting that occurred during the second fiscal quarter of the period covered by this report that have materially affected, or are reasonably likely to materially affect, the registrant's internal control over financial reporting. ITEM 3. EXHIBITS. (a) A separate certification for each principal executive officer and principal financial officer of the registrant as required by Rule 30a-2 under the Act (17 CFR 270.30a-2). Filed herewith. SIGNATURES [See General Instruction F] 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) Pioneer Municipal High Income Trust By (Signature and Title)* /s/ John F. Cogan, Jr. John F. Cogan, Jr, President Date March 31, 2009 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/ John F. Cogan, Jr. John F. Cogan, Jr., President Date March 31, 2009 By (Signature and Title)* /s/ Mark Bradley Mark Bradley, Treasurer Date March 31, 2009 * Print the name and title of each signing officer under his or her signature.