OMB APPROVAL OMB Number: 3235-0578 Expires: May 31, 2006 Estimated average burden hours per response..... 20.0 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 811-21043 Pioneer 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: March 31 Date of reporting period: December 31, 2005 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 High Income Trust SCHEDULE OF INVESTMENTS 12/31/05 (unaudited) Principal Amount USD ($) Value COLLATERIZED MORTGAGE OBLIGATIONS - 1.1% of Net Assets Diversified Financials - 1.1% 4,860,000 Tower 2004-2A F, 6.376%, 12/15/14 (144A) $ 4,846,547 TOTAL COLLATERIZED MORTGAGE OBLIGATIONS $ 4,846,547 (Cost $4,860,000) CORPORATE BONDS & NOTES - 119.8% of Net Assets Energy - 9.4% Oil & Gas Equipment & Services - 2.6% 6,200,000 J. Ray McDermott SA, 11.0%, 12/15/13 (14 $ 7,316,000 2,380,000 SemGroup L.P., 8.75%, 11/15/15 (144A) 2,433,550 1,120,000 Targa Resources, Inc., 8.5%, 11/1/13 (14 1,148,000 $ 10,897,550 Oil & Gas Exploration & Production - 6.2% 9,784,000 Baytex Energy, Ltd., 9.625%, 7/15/10 $ 10,273,200 1,570,000 Clayton William Energy, 7.75%, 8/1/13 1,507,200 1,735,000 Delta Petroleum Corp., 7.0%, 4/1/15 1,600,537 5,000,000 Energy Partners, Ltd., 8.75%, 8/1/10 5,125,000 5,300,000 PetroQuest Energy, Inc., 10.375%, 5/15/1 5,538,500 2,135,000 Stone Energy Corp., 6.75%, 12/15/14 2,022,913 $ 26,067,350 Oil & Gas Storage & Transportation - 0.6% 2,688,000 Transmontaigne, Inc., 9.125%, 6/1/10 $ 2,640,960 Total Energy $ 39,605,860 Materials - 25.9% Commodity Chemicals - 3.2% 4,635,000 ARCO Chemical Co., 9.8%, 2/1/20 $ 5,202,787 2,900,00(a)Aventine Renewable Energy, 10.491%, 12/1 3,001,500 5,000,000 Invista, 9.25%, 5/1/12 (144A) 5,337,500 $ 13,541,787 Diversified Chemicals - 3.7% 385,000 Ashtead Holdings Plc, 8.625%, 8/1/15 (14 $ 405,213 810,000 Braskem SA, 9.375%, 6/1/15 (144A) 891,000 2,550,000 Braskem SA, 11.75%, 1/22/14 3,149,250 EUR7,870,000 Huntsman International LLC, 10.125%, 7/1 9,607,976 EUR1,190,000 Nell AF S.a.r.l., 8.375%, 8/15/15 (144A) 1,424,721 $ 15,478,160 Specialty Chemicals - 10.8% 3,700,000 Basell Finance Co., 8.1%, 3/15/27 (144A) $ 3,385,500 6,060,00(b)Crystal US Holdings, 0.0%, 10/1/14 4,408,650 5,800,000 Ferro Corp., 7.125%, 4/1/28 5,899,992 1,300,000 Ferro Corp., 7.625%, 5/1/13 1,327,417 4,500,000 Methanex Corp., 8.75%, 8/15/12 5,006,250 7,100,000 OM Group, Inc., 9.25%, 12/15/11 6,940,250 5,970,00(d)PolyOne Corp., 8.875%, 5/1/12 5,850,600 6,175,000 Resolution Performance Products LLC, 13. 6,530,063 EUR4,970,000 Rhodia SA, 9.25%, 6/1/11 6,243,424 $ 45,592,146 Construction Materials - 0.5% 2,225,000 RMCC Acquisition Co., 9.5%, 11/1/12 (144 $ 2,236,125 Metal & Glass Containers - 2.3% 1,945,000 Anchor Glass Container Corp., 11.0%, 2/1 $ 1,419,850 4,020,000 Greif Bros. Corp., 8.875%, 8/1/12 4,281,300 4,135,000 Vitro Envases, 10.75%, 7/23/11 (144A) 4,217,700 $ 9,918,850 Paper Packaging - 1.6% 1,685,000 Graham Packaging Co., L.P., 9.875%, 10/1 $ 1,642,875 5,290,000 Graphic Packaging International, Inc., 9 5,051,950 $ 6,694,825 Aluminum - 0.3% 1,440,000 Aleris International, Inc., 9.0%, 11/15/ $ 1,483,200 Diversified Metals & Mining - 1.2% 4,600,000 Freeport-McMoRan Copper & Gold, Inc., 10 $ 5,054,250 Steel - 1.5% 2,900,000 CSN Islands VIII Corp., 9.75%, 12/16/13 $ 3,215,375 880,000 (b)CSN Islands IX Corp., 10.5%, 1/15/15 (14 981,200 2,485,000 Edgen Acquisition Corp., 9.875%, 2/1/11 2,410,450 $ 6,607,025 Forest Products - 0.4% 1,645,000 Mandra Forestry Holdings, Ltd., 12.0%, 5 $ 1,579,200 Paper Products - 0.4% 1,875,000 Mercer International, Inc., 9.25%, 2/15/ $ 1,579,688 Total Materials $ 109,765,256 Capital Goods - 5.6% Building Products - 1.7% 3,135,00(a)Builders FirstSource, Inc., 8.59%, 2/15/ $ 3,189,862 4,185,000 U.S. Concrete, Inc., 8.375%, 4/1/14 4,174,538 $ 7,364,400 Construction & Engineering - 0.3% 1,250,000 Dycom Industries, Inc., 8.125%, 10/15/15 $ 1,250,000 Heavy Electrical Equipment - 2.1% 4,790,000 Altra Industrial Motion, 9.0%, 12/1/11 ( $ 4,646,300 3,975,000 Hawk Corp., 8.75%, 11/1/14 4,014,750 $ 8,661,050 Construction & Farm Machinery & Heavy Truck - 1.2% 3,300,000 American Rock Salt Co., LLC, 9.5%, 3/15/ $ 3,333,000 1,980,00(d)Hines Nurseries, Inc., 10.25%, 10/1/11 1,940,400 $ 5,273,400 Industrial Machinery - 0.3% 1,217,000 Manitowac Co., Inc., 10.5%, 8/1/12 $ 1,350,870 Total Capital Goods $ 23,899,720 Commercial Services & Supplies - 10.2% Diversified Commercial & Professional Services - 5.4% 3,500,000 Allied Security Escrow, 11.375%, 7/15/11 $ 3,374,150 1,850,000 Brickman Group, Ltd., Series B, 11.75%, 2,048,875 4,455,000 Cardtronics, Inc., 9.25%, 8/15/13 (144A) 4,432,725 3,230,000 Cornell Companies, Inc., 10.75%, 7/1/12 3,343,050 3,820,000 Park-Ohio Industries, Inc., 8.375%, 11/1 3,342,500 6,695,00(d)United Rentals North America, Inc., 7.75 6,527,625 $ 23,068,925 Human Resource & Employment Services - 0.6% 2,700,000 Knowledge Learning Corp., Inc., 7.75%, 2 $ 2,565,000 Environmental & Facilities Services - 4.2% 6,275,000 Clean Harbors, Inc., 11.25%, 7/15/12 $ 7,059,375 5,020,000 Hydrochem Industrial Services, Inc., 9.2 4,819,200 5,800,000 Waste Services, Inc., 9.5%, 4/15/14 5,800,000 $ 17,678,575 Total Commerical Service & Supplies $ 43,312,500 Transportation - 14.1% Airlines - 3.3% 1,316,928 American Airlines, Inc., 7.379%, 11/23/1 $ 1,079,686 1,100,000 American Airlines, Inc., 10.38%, 3/4/06 1,097,250 2,065,00(d)AMR Corp., 9.0%, 8/1/12 1,791,387 2,440,000 AMR Corp., 9.8%, 10/1/21 1,823,900 3,200,000 AMR Corp., 10.2%, 3/15/20 2,424,000 6,000,000 Continental Airlines, Inc., Series D, 7. 5,911,891 $ 14,128,114 Marine - 8.5% 3,899,00(b)H-Lines Finance Holding, 0.0%, 4/1/13 $ 3,226,422 NOK27,300,0(b)Kvaerner ASA, 0.0%, 10/30/11 3,628,577 8,897,00(b)Kvaerner ASA, 0.0%, 10/30/11 8,363,180 8,000,000 Seabulk International, Inc., 9.5%, 8/15/ 8,990,000 7,350,000 Ship Finance International, Ltd., 8.5%, 6,872,250 985,000 Stena AB, 7.0%, 12/1/16 901,275 1,000,000 Stena AB, 7.5%, 11/1/13 960,000 2,900,000 Trailer Bridge, Inc., 9.25%, 11/15/11 2,983,375 $ 35,925,079 Railroads - 1.7% 4,525,000 Atlantic Express Transportation Corp., 1 $ 3,936,750 2,500,000 Grupo Transportacion Ferroviaria Mexicana, SA de CV, 9.375%, 5/1/12 (144A) 2,737,500 400,000 Grupo Transportacion Ferroviaria Mexicana, SA de CV, 10.25%, 6/15/07 422,000 $ 7,096,250 Trucking - 0.5% 2,175,000 Greenbrier Companies, Inc., 8.375%, 5/15 $ 2,218,500 Airport Services - 0.1% 535,000 K&F Acquisition, Inc., 7.75% 11/15/14 $ 540,350 Total Transportation $ 59,908,293 Automobiles & Components - 4.7% Auto Parts & Equipment - 2.4% 3,590,000 Cooper-Standard Automotive, Inc., 8.375% $ 2,728,400 5,475,000 Stanadyne Corp., 10.0%, 8/15/14 5,256,000 2,000,000 UGS Corp., 10.0%, 6/1/12 2,180,000 $ 10,164,400 Tires & Rubber - 1.7% 7,010,000 Goodyear Tire & Rubber Co., 9.0%, 7/1/15 $ 6,904,850 Automobile Manufacturers - 0.6% 3,000,000 Ford Motor Credit Co., 7.375%, 10/28/09 $ 2,660,658 Total Automobiles & Components $ 19,729,908 Consumer Durable & Apparel - 0.4% Homebuilding - 0.4% 1,165,000 WCI Communities, Inc., 7.875%, 10/1/13 $ 1,098,013 700,000 William Lyon Homes, Inc., 7.625%, 12/15/ 617,750 $ 1,715,763 Total Consumer Durable & Apparel $ 1,715,763 Consumer Services - 1.8% Hotels, Resorts & Cruise Lines - 1.2% 2,990,00(d)MeriStar Hospitality Operating Partnersh $ 3,150,713 2,050,000 Trump Entertainment Resorts, Inc., 8.5%, 1,998,750 $ 5,149,463 Leisure Facilities - 0.6% 2,500,000 True Temper Sports, Inc., 8.375%, 9/15/1 $ 2,250,000 Total Consumer Services $ 7,399,463 Media - 5.0% Broadcasting & Cable TV - 2.3% 2,170,000 Cablemas SA de CV, 9.375%, 11/15/15 (144 $ 2,224,250 2,855,00(a)Cleveland Unlimited, Inc., 12.73%, 12/15 2,883,550 EUR3,750,000 Kabel Deutschland GMBH, 10.75%, 7/1/14 ( 4,920,941 $ 10,028,741 Movies & Entertainment - 0.8% 3,000,000 LodgeNet Entertainment Corp., 9.5%, 6/15 $ 3,262,500 Publishing - 1.9% 5,085,000 Sheridan Acquisition Corp., 10.25%, 8/15 $ 5,231,194 3,700,00(b)Visant Holding Corp., 0.0%, 12/1/13 2,738,000 $ 7,969,194 Total Media $ 21,260,435 Retailing - 4.7% Distributors - 0.8% 3,535,000 Intcomex, Inc., 11.75%, 1/15/11 (144A) $ 3,473,137 Department Stores - 1.0% 3,800,000 J.C. Penney Co., Inc., 8.125%, 4/1/27 $ 3,980,500 General Merchandise Stores Retail - 0.7% EUR2,500,000 Ray Acquisition SCA, 9.375%, 3/16/15 (14 $ 3,125,811 Computer & Electronics Retailing - 0.2% 695,000 GSC Holdings Corp., 8.0%, 10/1/12 (144A) $ 653,300 Specialty Stores - 0.9% 3,840,000 Asbury Automotive Group, Inc., 9.0%, 6/1 $ 3,840,000 Automotive Retail - 1.1% 5,370,000 Pep Boys-Manny, Moe & Jack, 7.5%, 12/15/ $ 4,779,300 Total Retailing $ 19,852,048 Food & Staples Retailing - 2.1% Drug Retail - 0.7% 550,000 (a)Duane Reade, Inc., 8.991% 12/15/10 $ 511,500 3,700,00(d)Duane Reade, Inc., 9.75%, 8/1/11 2,479,000 $ 2,990,500 Food Distributors - 1.4% 2,480,000 Doane Pet Care Co., 10.625%, 11/15/15 (1 $ 2,585,400 3,380,000 Wornick Co., 10.875%, 7/15/11 3,464,500 $ 6,049,900 Total Food & Staples Retailing $ 9,040,400 Food, Beverage & Tobacco - 1.7% Soft Drinks - 1.7% 5,885,000 Cia Brasileira de Bebida, 10.5%, 12/15/1 $ 7,238,550 Total Food, Beverage & Tobacco $ 7,238,550 Health Care Equipment & Services - 5.3% Health Care Equipment & Services - 2.2% 1,800,000 Accellent, Inc., 10.5%, 12/1/13 (144A) $ 1,845,000 5,265,00(d)Hanger Orthopedic Group, Inc., 10.375%, 5,265,000 2,900,00(a)Medical Services Co., 11.65%, 10/15/11 ( 2,233,000 $ 9,343,000 Health Care Services - 2.5% 2,160,000 AMR HoldCo/Emcare HoldCo, 10.0%, 2/15/15 $ 2,305,800 1,500,000 National Nephrology Associates, Inc., 9. 1,661,250 2,000,000 NDCHealth Corp., 10.5%, 12/1/12 2,285,000 4,055,000 Rural/Metro Corp., 9.875%, 3/15/15 (144A 4,136,100 $ 10,388,150 Managed Health Care - 0.6% 2,335,000 PacifiCare Health Systems, Inc., 10.75%, $ 2,501,369 Total Health Care Equipment & Services $ 22,232,519 Pharmaceuticals & Biotechnology - 1.4% Pharmaceuticals - 1.4% 6,650,000 Warner Chilcott Corp., 8.75%, 2/1/15 (14 $ 6,118,000 Total Pharmaceuticals & Boitechnology $ 6,118,000 Diversified Financials - 7.0% Other Diversified Financials Services - 4.0% 5,587,00(b)Alamosa Delaware, Inc., 12.0%, 7/31/09 $ 6,110,781 6,135,000 Dollar Financial Group, 9.75%, 11/15/11 6,319,050 EUR2,000,000 MDP Acquisitions Plc, 10.125%, 10/1/12 2,524,240 2,100,00(a)Pipe Acquisition Finance Plc, 10.913%, 1 2,084,250 $ 17,038,321 Specialized Finance - 3.0% 1,500,000 Digicel, Ltd., 9.25%, 9/1/12 (144A) $ 1,541,250 2,435,000 Galaxy Entertainment Finance Co., Ltd., 2,471,525 7,950,000 GATX Financial Corp., 8.875%, 6/1/09 8,770,042 $ 12,782,817 Total Diversified Financials $ 29,821,138 Insurance - 3.4% Life & Health Insurance - 1.3% 5,725,000 Presidential Life Corp., 7.875%, 2/15/09 $ 5,667,750 Multi-Line Insurance - 1.3% 5,300,000 Allmerica Financial Corp., 7.625%, 10/15 $ 5,435,309 Property & Casualty Insurance - 0.8% 3,380,000 Kingsway America, Inc., 7.5%, 2/1/14 $ 3,482,613 Total Insurance $ 14,585,672 Technology Hardware & Equipment - 4.7% Communications Equipment - 0.7% 2,900,000 Lucent Technologies, Inc., 7.25%, 7/15/0 $ 2,921,750 Electronic Equipment Manufacturers - 0.1% 215,000 General Cable Corp., 9.5%, 11/15/10 $ 227,900 Electronic Manufacturing Services - 1.0% 4,000,000 Sanmina-SCI Corp., 10.375%, 1/15/10 $ 4,420,000 Office Electronics - 2.9% 11,830,000 Xerox Capital Trust I, 8.0%, 2/1/27 $ 12,184,900 Total Technology Hardware & Equipment $ 19,754,550 Telecommunication Services - 8.5% Integrated Telecommunication Services - 2.4% 5,212,000 Eschelon Operating Co., 8.375%, 3/15/10 $ 4,821,100 4,025,000 GCI, Inc., 7.25%, 2/15/14 3,984,750 530,000 (a)NTELOS Holdings Corp., 12.9%, 10/15/13 ( 528,675 1,400,00(b)Zeus Special Subsidiary, Ltd., 0.0%, 2/1 920,500 $ 10,255,025 Wireless Telecommunications Services - 6.1% 3,900,000 Horizon PCS, Inc., 11.375%, 7/15/12 $ 4,475,250 2,200,00(b)Inmarsat Finance II Plc, 0.0%, 11/15/12 1,834,250 5,150,000 Mobifon Holdings BV, 12.5%, 7/31/10 5,974,000 3,230,000 Mobile Telesystems, 9.75%, 1/30/08 (144A 3,423,800 3,000,00(a)Rural Cellular Corp., 10.041%, 11/1/12 ( 3,022,500 691,000 Tele Norte Leste Participacoes SA, 8.0%, 732,460 5,525,000 UbiquiTel Operating Co., 9.875%, 3/1/11 6,118,938 $ 25,581,198 Total Telecommunication Services $ 35,836,223 Utilities - 3.9% Electric Utilities - 3.5% 2,000,000 Aes Chivor SA ESP, 9.75%, 12/30/14 (144 $ 2,160,000 1,822,500 Empresa Electrica Guacolda SA, 8.625%, 4 2,042,040 6,370,693 Ormat Funding Corp., 8.25%, 12/30/20 6,434,400 4,280,000 VeraSun Energy Corp., 9.875%, 12/15/12 ( 4,344,200 $ 14,980,640 Multi-Utilities - 0.4% 1,800,000 Reliant Energy, Inc., 6.75%, 12/15/14 $ 1,570,500 Total Utilities $ 16,551,140 TOTAL CORPORATE BONDS & NOTES (Cost $481,110,399) $ 507,627,438 CONVERTIBLE BONDS & NOTES - 1.1% of Net Assets Consumer Services - 0.9% Specialized Consumer Services - 0.9% 4,000,000 SCI Systems, Inc., 3.0%, 3/15/07 $ 3,830,000 Total Consumer Services $ 3,830,000 Software & Services - 0.2% Data Processing & Outsourced Services - 0.2% 850,000 Pegasus Solutions, Inc., 3.875%, 7/15/23 $ 826,625 Total Software & Services $ 826,625 TOTAL CONVERTIBLE BONDS & NOTES (Cost $4,400,120) $ 4,656,625 MUNICIPAL BONDS - 7.7% of Net Assets Indiana - 3.1% 1,650,000 East Chicago Industrial Pollution Ctl. R $ 1,747,746 3,000,000 East Chicago Industrial Pollution Ctl. R 3,106,140 3,665,000 Indiana Dev. Fin. Auth. Pollution Ctl. R 3,797,746 4,250,000 Indiana Dev. Fin. Auth. Rev., 5.75%, 10/ 4,415,877 $ 13,067,509 Michigan - 0.4% 3,000,000 Wayne Charter County, Spl. Arpt. Facs. R $ 1,571,520 New Jersey - 2.1% 4,525,000 New Jersey Economic Dev. Auth. Rev., 7.0 $ 4,400,065 4,000,000 Tobacco Settlement Financing Corp., 7.0% 4,559,720 $ 8,959,785 New York - 0.9% 3,475,000 New York City Ind. Dev. Agcy., British Airways Plc Proj., 7.625%, 12/1/32 $ 3,750,359 North Carolina - 1.2% 4,800,000 Charlotte, Spl. Facs. Rev., Charlotte/Douglas Int'l Airport, 5.6%, 7/1/27 $ 3,381,504 2,000,000 Charlotte, Spl. Facs. Rev., Charlotte/Douglas Int'l Airport, 7.75%, 2/1/28 1,823,740 $ 5,205,244 TOTAL MUNICIPAL BONDS (Cost $26,232,644) $ 32,554,417 SOVEREIGN DEBT OBLIGATIONS - 2.1% of Net Assets Brazil - 0.8% ITL4,800,00(b)Banco Nacional de Desenvolimento Bndes, $ 3,245,747 Ecuador - 0.7% 3,515,00(b)Federal Republic of Ecuador, 9.0%, 8/15/ $ 3,198,650 Russia - 0.6% 2,320,00(b)Russian Federation, 5.0%, 3/31/30 $ 2,619,048 TOTAL SOVEREIGN DEBT OBLIGATIONS (Cost $6,009,882) $ 9,063,445 Shares COMMON STOCKS - 0.9% of Net Assets Pharmaceuticals & Biotechnology - 0.9% Pharmaceuticals - 0.9% 120,325 IVAX Corp. $ 3,769,790 Total Pharmaceuticals & Biotechnology $ 3,769,790 TOTAL COMMON STOCKS (Cost $2,462,500) $ 3,769,790 WARRANTS - 0.0% of Net Assets Materials - 0.0% Forest Products - 0.0% 1,645 Mandra Forestry Holdings, Ltd. - CW13, E $ - Total Materials $ - Transportation - 0.0% Railroads - 0.0% 4,525 Atlantic Express Transportation Corp., E $ - Total Transportation $ - TOTAL WARRANTS (Cost $0) $ - TEMPORARY CASH INVESTMENTS - 4.7% of Net Assets Security Lending Collateral - 4.7% 19,667,338 Securities Lending Investment Fund, 4.24 $ 19,667,338 TOTAL TEMPORARY CASH INVESTMENTS (Cost $19,667,338) $ 19,667,338 TOTAL INVESTMENTS IN SECURITIES - 137.4% (Cost $544,742,883) (c) (e) $ 582,185,600 OTHER ASSETS AND LIABILITIES - (1.7)% $ (7,364,734) PREFERRED SHARES AT REDEMPTION VALUE, INCLUDING DIVIDENDS PAYABLE - (35.7)% $ (151,060,830) NET ASSETS APPLICABLE TO COMMON SHAREOWNERS - 100.0% $ 423,760,036 NR Security not rated by S&P or Moody's. (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 December 31, 2005, the value of these securities amounted to $133,677,635 or 31.6% of total net assets applicable to common shareholders. * Security is in default and is non-income producing. ** Non-income producing. (a) Floating rate note. (b) Debt obligation initially issued at one coupon which converts to a higher coupon at a specific date. The rate shown is the rate at period end. (c) At December 31, 2005, the net unrealized gain on investments based on cost for federal income tax purposes of $545,099,869 was as follows: Aggregate gross unrealized gain for all investments in which there is an excess of value over tax cos $ 45,994,665 Aggregate gross unrealized loss for all investments in which there is an excess of tax cost over valu (8,908,934) Net unrealized gain $ 37,085,731 For financial reporting purposes net unrealized gain was $37,442,717 and cost of investments aggregated $544,742,883. (d) At December 31, 2005, the following securities were out on loan: Principal Market Amount Description Value $ 1AMR Corp., 9.0%, 8/1/12 $ 1,701,168 3Duane Reade, Inc., 9.75%, 8/1/11 2,355,050 Hanger Orthopedic Group, Inc., 10.375%, 5,001,750 Hines Nurseries, Inc., 10.25%, 10/1/11 582,120 2,MeriStar Hospitality Operating Partnersh 2,993,177 5,PolyOne Corp., 8.875%, 5/1/12 5,315,520 United Rentals North America, Inc., 7.75 827,775 $ 18,776,560 (e) Distribution of investments by country of issue, as a percentage of total holdings, is as follows: United States 74.6% Canada 4.5 Norway 3.6 Brazil 2.9 France 2.3 Australia 1.7 Mexico 1.5 Panama 1.2 Romania 1.0 Russia 1.0 Germany 0.9 Cayman Islands 0.7 Great Britain 0.7 Ecuador 0.6 Netherlands 0.6 Colombia 0.4 Ireland 0.4 Bermuda 0.3 Chile 0.3 China 0.3 Sweden 0.3 Luxembourg 0.2 100.0 % Note: Principal amounts are denominated in U.S. dollars unless otherwise denoted. EURO Euro ITL Italian Lira NOK Norwegian Krone Purchases and sales of securities (excluding temporary cash investments) for the period ended December 31, 2005, aggregated $119,903,172 and $80,206,545, respectively. 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 certifying officers have determined that the registrant's disclosure controls and procedures are effective based on an evaluation of these controls and procedures as of a date within 90 days prior to 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 was no significant change in the registrant's internal controls over financial reporting 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. 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 High Income Trust By (Signature and Title)* /s/ John F. Cogan, Jr. John F. Cogan, Jr, President Date February 28, 2006 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 February 28, 2006 By (Signature and Title)* /s/ Vincent Nave Vincent Nave, Treasurer Date February 28, 2006 * Print the name and title of each signing officer under his or her signature.