UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 FORM N-Q QUARTERLY SCHEDULE OF PORTFOLIO HOLDINGS OF REGISTERED MANAGEMENT INVESTMENT COMPANY Investment Company Act file number: 811-06590 Morgan Stanley Insured Municipal Income Trust (Exact name of registrant as specified in charter) 522 Fifth Avenue, New York, New York 10036 (Address of principal executive offices) (Zip code) Ronald E. Robison 522 Fifth Avenue, New York, New York 10036 (Name and address of agent for service) Registrant's telephone number, including area code: 212-296-6990 Date of fiscal year end: October 31, 2007 Date of reporting period: July 31, 2007 ITEM 1. SCHEDULE OF INVESTMENTS. The Trust's schedule of investments as of the close of the reporting period prepared pursuant to Rule 12-12 of Regulation S-X is as follows: Morgan Stanley Insured Municipal Income Trust PORTFOLIO OF INVESTMENTS JULY 31, 2007 (UNAUDITED) PRINCIPAL AMOUNT IN COUPON MATURITY THOUSANDS RATE DATE VALUE TAX-EXEMPT MUNICIPAL BONDS (156.4%) ARIZONA (0.8%) $ 2,500 University of Arizona, 2003 Ser B COPs (Ambac) 5.00% 06/01/23 $ 2,586,025 -------------- CALIFORNIA (30.9%) 20,000 Anaheim Public Financing Authority, Electric System District 4.50 10/01/37 19,130,600 Facilities, Ser 2007-A (MBIA) +++ 3,000 California, Economic Recovery Ser 2004 A (MBIA) 5.00 07/01/15 3,193,590 8,000 California, Ser 2007 (MBIA) 4.25 08/01/33 7,378,320 10,000 California Infrastructure & Economic Development Bank, Bay Area Toll Bridges Seismic Retrofit 1st Lien Ser 2003 A 5.00 01/01/28 10,908,800 (Ambac) (ETM) 5,000 California Infrastructure & Economic Development Bank, Bay Area Toll Bridges Seismic Retrofit 1st Lien Ser 2003 A 5.00 01/01/28 5,454,400 (FGIC) (ETM) 6,000 Golden State Tobacco Securitization Corporation, Enhanced 5.00 06/01/38 6,134,220 Asset Backed Ser 2005 A (FGIC) 9,000 Long Beach, Harbor Refg Ser 1998 A (AMT) (FGIC) 6.00 05/15/18 10,196,640 3,000 Los Angeles, Ser 2004 A (MBIA) 5.00 09/01/24 3,156,900 5,000 Los Angeles Department of Water & Power, Water 5.00 07/01/24 5,256,150 2004 Ser C (MBIA) 4,000 Oxnard Financing Authority, Water Ser 2004 C (XLCA) 5.00 06/01/28 4,115,120 3,000 Sacramento County Sanitation District Financing Authority, 5.00 12/01/36 3,127,050 Sacramento Regional Ser 2006 (FGIC) 5,000 San Diego County Water Authority, Ser 2002 A COPs (MBIA) 5.00 05/01/27 5,170,400 5,000 San Diego County Water Authority, Ser 2004 A COPs (FSA) 5.00 05/01/29 5,166,650 3,000 San Francisco City & County, City Buildings 4.50 09/01/37 2,872,590 Ser 2007 A COPs (FGIC) 2,000 University of California, Ser 2003 B (Ambac) 5.00 05/15/22 2,078,420 3,120 University of California, Ser 2007-J (FSA)+++ 4.50 05/15/31 3,036,524 2,880 University of California, Ser 2007-J (FSA)+++ 4.50 05/15/35 2,802,946 -------------- 99,179,320 -------------- COLORADO (2.3%) 4,000 Arkansas River Power Authority, Power Ser 2006 (XLCA) 5.25 10/01/40 4,206,160 3,000 Denver Convention Center Hotel Authority, Refg Ser 2006 5.00 12/01/30 3,106,530 (XLCA) -------------- 7,312,690 -------------- DISTRICT OF COLUMBIA (5.1%) 2,000 District of Columbia Ballpark, Ser 2006 B-1 (FGIC) 5.00 02/01/31 2,073,560 3,000 District of Columbia, American Association for the 5.125 01/01/27 3,056,130 Advancement of Science Ser 1997 (Ambac) 5,000 District of Columbia, Refg Ser 1993 B (Ambac) 5.50 06/01/09 5,153,800 6,000 District of Columbia, Refg Ser 1993 B (FSA) 5.50 06/01/10 6,221,520 -------------- 16,505,010 -------------- FLORIDA (7.4%) 15,000 Miami-Dade County School Board, 2003 Ser A (FGIC) 5.00 08/01/29 15,339,150 3,000 Orange County School Board, Ser 2001 A COPs (Ambac) 5.25 08/01/14 3,187,860 5,000 Tampa Bay Water Authority, Ser 2001 A (FGIC) 5.00 10/01/28 5,100,400 -------------- 23,627,410 -------------- GEORGIA (3.9%) 5,000 Atlanta, Airport Ser 2004 C (FSA) 5.00 01/01/33 5,139,500 5,000 Atlanta, Water & Wastewater, Ser 2004 (FSA) 5.00 11/01/23 5,214,100 2,000 Augusta, Water & Sewer Ser 2004 A (FSA) 5.25 10/01/39 2,102,780 -------------- 12,456,380 -------------- HAWAII (1.6%) 5,000 Hawaii Department of Budget and Finance, Hawaiian Electric Co 6.20 11/01/29 5,263,550 Ser 1999 C (AMT) (Ambac) -------------- ILLINOIS (11.0%) 15,000 Chicago, Neighborhoods Alive 21 Ser 2001 A (FGIC) 5.50 01/01/11+ 15,811,800 5,000 Chicago, O'Hare Int'l Airport, Third Lien Ser 2005 A (MBIA) 5.25 01/01/25 5,308,700 2,000 Illinois Finance Authority, Swedish American Hospital Ser 2004 5.00 11/15/31 2,053,300 (Ambac) 4,000 Illinois Toll Highway Authority, Priority Refg 1998 Ser A (FSA) 5.50 01/01/15 4,383,000 3,000 Metropolitan Pier & Explosion Authority, McCormick Place Refg Ser 2002 B (MBIA) 0.00# 06/15/18 2,516,490 5,000 Metropolitan Pier & Explosion Authority, McCormick Place Ser 2002 A (MBIA) 5.25 06/15/42 5,238,650 -------------- 35,311,940 -------------- INDIANA (1.4%) 2,000 Indiana Health Facilities Financing Authority, Community Health 5.00 05/01/35 2,060,060 Ser 2005 A (Ambac) 2,400 Marion County Convention & Recreational Facilities Authority, 5.00 06/01/19 2,485,848 Refg Ser 2003 A (Ambac) -------------- 4,545,908 -------------- LOUISIANA (1.3%) 4,000 Lafayette, Utilities Ser 2004 (MBIA) 5.25 11/01/25 4,259,920 -------------- MASSACHUSETTS (3.6%) 3,275 Massachusetts Municipal Wholesale Electric Company, 1993 Ser A 5.00 07/01/10 3,333,229 (Ambac) (ETM) 8,000 Massachusetts Turnpike Authority, Metropolitan Highway 1997 5.00 01/01/37 8,085,720 Ser A (MBIA) +++ -------------- 11,418,949 -------------- MICHIGAN (0.8%) 2,390 Detroit, Sewage Refg Ser 2003 A (FSA) 5.00 07/01/28 2,456,370 -------------- MINNESOTA (1.6%) 5,000 Minneapolis - St Paul Metropolitan Airports Commission, 5.25 01/01/11+ 5,230,900 Ser 2001 C (FGIC) -------------- MISSOURI (0.8%) 2,500 Missouri Joint Municipal Electric Utility Commission Plum Point 5.00 01/01/26 2,589,350 Ser 2006 (MBIA) -------------- MONTANA (0.6%) 2,000 Montana Facility Finance Authority, Benefits Health Care Ser 2007 5.00 01/01/37 2,061,280 (AGC) -------------- NEBRASKA (1.6%) 5,000 Nebraska Public Power District, 2003 Ser A (Ambac) 5.00 01/01/35 5,148,850 -------------- NEVADA (3.9%) 5,080 Las Vegas Water District, Impr & Refg Ser 2003 A (FGIC) 5.25 06/01/19 5,348,326 7,000 Nevada Department of Business & Industry, Las Vegas Monorail 5.375 01/01/40 7,173,950 1st Tier Ser 2000 (Ambac) -------------- 12,522,276 -------------- NEW HAMPSHIRE (0.4%) 1,300 New Hampshire Health & Education Facilities Authority, University 5.125 07/01/33 1,348,191 of New Hampshire Ser 2001 (Ambac) -------------- NEW JERSEY (2.3%) 2,000 Delaware River Port Authority, New Jersey & Pennsylvania Ser 1995 (FGIC)* 5.50 01/01/26 2,014,420 4,000 New Jersey Transportation Trust Fund Authority, Ser 2005 C (FGIC) 5.25 06/15/20 4,285,800 1,000 University of Medicine and Dentistry, Ser 2004 COPs (MBIA) 5.00 06/15/29 1,035,500 -------------- 7,335,720 -------------- NEW YORK (18.8%) 16,000 Hudson Yards Infrastructure Corporation, 2007 Ser A (MBIA) +++ 4.50 02/15/47 15,261,840 3,000 Long Island Power Authority, Refg Ser 2003 C (FSA) 5.00 09/01/28 3,091,020 4,000 Long Island Power Authority, Ser 2006 A (XLCA) 5.00 12/01/26 4,163,440 3,000 Metropolitan Transportation Authority, Dedicated Tax Fund Refg 5.25 11/15/24 3,172,590 Ser 2002 A (FSA) 10,000 Metropolitan Transportation Authority, Transportation 5.00 11/15/25 10,349,400 Refg Ser 2002 A (FGIC) 2,000 New York City Industrial Development Agency, Queens Baseball Stadium Ser 2006 (Ambac) 5.00 01/01/31 2,086,140 2,500 New York City Industrial Development Agency, Yankee 5.00 03/01/46 2,574,225 Stadium Ser 2006(FGIC) 1,735 New York City Transitional Finance Authority, 5.25 08/01/21 1,831,206 2000 Ser C (Ambac) 2,500 New York City Transitional Finance Authority, 5.25 08/01/22 2,634,575 2000 Ser C (Ambac) ++ 4,200 New York State Dormitory Authority, School District Ser 2002 E 5.50 10/01/17 4,495,638 (MBIA) 10,000 Triborough Bridge & Tunnel Authority, Refg 2002 E (MBIA) 5.25 11/15/22 10,575,300 -------------- 60,235,374 -------------- NORTH CAROLINA (2.9%) 6,000 North Carolina Municipal Power Agency # 1, Catawba 5.25 01/01/19 6,309,600 Ser 2003 A (MBIA) 3,000 University of North Carolina at Wilmington, Student Housing 5.00 06/01/36 3,082,950 Ser 2005 COPs (FGIC) -------------- 9,392,550 -------------- OHIO (0.3%) 1,005 Cleveland, Ohio, Waterworks Impr & Refg 1998 Ser I (FSA) 5.00 01/01/23 1,018,728 -------------- OREGON (1.0%) 3,000 Oregon Department of Administrative Services, Ser 2005 B COPs 5.00 11/01/24 3,128,490 (FGIC) -------------- PENNSYLVANIA (5.3%) 5,000 Allegheny County Hospital Development Authority, Pittsburgh 5.625 08/15/18 5,321,350 Mercy Health Ser 1996 (Ambac) (ETM) 2,000 Delaware County Industrial Development Authority, Aqua Inc 5.00 11/01/37 2,037,760 Ser A 2005 (AMT) (FGIC) 4,110 Pennsylvania, First Ser 2003 (MBIA) +++ 5.00 01/01/13+ 4,337,941 5,000 Philadelphia, Water & Wastewater Ser 1998 (Ambac) 5.25 12/15/14 5,394,100 -------------- 17,091,151 -------------- RHODE ISLAND (3.4%) 10,000 Rhode Island Depositors Economic Protection Corporation, 6.00 08/01/17 10,881,400 Refg 1992 Ser B (MBIA) (ETM) -------------- SOUTH CAROLINA (5.0%) 1,500 Medical University Hospital Authority, FHA 5.25 02/15/25 1,580,610 Insured Mtge Ser 2004 A (MBIA) 10,000 South Carolina Public Service Authority, Santee Cooper, Ser 2003 A (Ambac) 5.00 01/01/27 10,340,800 4,000 South Carolina Public Service Authority, Santee Cooper, Ser 2006 A (MBIA) 5.00 01/01/36 4,151,480 -------------- 16,072,890 -------------- TEXAS (21.9%) 3,020 Amarillo Health Facilities Corporation, Baptist St Anthony's Hospital Ser 1998 (FSA) 5.50 01/01/16 3,290,230 5,075 Amarillo Health Facilities Corporation, Baptist St Anthony's Hospital Ser 1998 (FSA) 5.50 01/01/17 5,503,431 9,000 Dallas-Fort Worth International Airport, Ser 2003 A (AMT) 5.375 11/01/22 9,418,230 (FSA) 15,000 Houston, Combined Utility First Lien Refg 2004 Ser A (FGIC) 5.25 05/15/23 15,911,850 4,000 Houston, Public Impr & Refg Ser 2001 B (FSA) 5.50 03/01/17 4,214,440 10,000 Lower Colorado River Authority, Refg Ser 1999 A (FSA) 5.875 05/15/16 10,443,100 5,000 Lower Colorado River Authority, Refg Ser 2001 (FSA) 5.00 05/15/26 5,095,450 8,780 Lower Colorado River Authority, Refg Ser 2002 (MBIA) 5.00 05/15/31 8,998,710 3,000 San Antonio, Water & Refg Ser 2002 A (FSA) 5.00 05/15/32 3,080,040 4,000 Texas Turnpike Authority, Central Texas First Tier Ser 2002 A 5.50 08/15/39 4,235,720 (Ambac) -------------- 70,191,201 -------------- UTAH (1.6%) 5,000 Intermountain Power Agency, Utah, 2003 Ser A (FSA) 5.00 07/01/21 5,214,100 -------------- VIRGINIA (2.0%) 3,000 Alexandria Industrial Development Authority, Institute for 5.90 10/01/10+ 3,217,860 Defense Analysis Ser 2000 A (Ambac) 3,000 Richmond Metropolitan Authority, Refg Ser 2002 (FGIC) 5.25 07/15/22 3,324,210 -------------- 6,542,070 -------------- WASHINGTON (11.9%) 6,000 Cowlitz County, Public Utility District # 1, Production Ser 5.00 09/01/31 6,205,620 2006 (MBIA) 3,000 King County, Refg 1998 Ser B (MBIA) 5.25 01/01/34 3,043,650 5,000 King County, Sewer Refg 2001 (FGIC) 5.00 01/01/31 5,129,350 8,025 Port of Seattle, Passenger Facility Ser 1998 A (MBIA) +++ 5.00 12/01/23 8,163,040 5,000 Port of Seattle, Ser 2001 B (AMT) (MBIA) 5.625 02/01/24 5,189,600 2,890 Seattle, Water Refg 2003 (MBIA) 5.00 09/01/20 3,012,103 2,870 Seattle, Water Refg 2003 (MBIA) 5.00 09/01/23 2,970,220 2,500 Spokane School District #81, Ser 2005 (MBIA) 0.00## 12/01/23 2,429,075 2,000 Washington State Health Care Facilities Authority, Kadlec Medical 5.00 12/01/30 2,062,320 Center Ser 2006 A (AGC) -------------- 38,204,978 -------------- WEST VIRGINIA (1.0%) 2,900 West Virginia Water Development Authority, Loan Program II Refg 5.25 11/01/23 3,095,953, 2003 Ser B (Ambac) -------------- 485,055 TOTAL TAX-EXEMPT MUNICIPAL BONDS 502,228,924 ---------- (Cost $488,356,666) -------------- SHORT-TERM INVESTMENT (a) (4.5%) Investment Company 14,331 Morgan Stanley Institutional Liquidity Tax-Exempt Portfolio - ---------- Institutional Class (Cost $14,331,162) 14,331,162 -------------- 499,386 TOTAL INVESTMENTS (Cost $502,687,828) 516,560,086 ---------- -------------- \ FLOATING RATE NOTE OBLIGATIONS RELATED TO SECURITIES HELD (-14.2%) (45,580) Notes with interest rates ranging from 3.61% to 3.67% at July 31, 2007 and ---------- contractual maturities of collateral ranging from 01/01/13 to 02/15/47 (b)++++ (Cost $(45,580,000)) (45,580,000) -------------- 453,806 TOTAL NET INVESTMENTS ========== (COST $457,107,828) (c) (d) 146.7% 470,980,086 OTHER ASSETS IN EXCESS OF LIABILITIES 1.7 5,301,754 PREFERRED SHARES OF BENEFICIAL INTEREST (48.4) (155,290,000) ------ -------------- NET ASSETS APPLICABLE TO COMMON SHAREHOLDERS 100.0% $ 320,991,840 ====== ============== Note: The categories of investments are shown as a percentage of net assets applicable to common shareholders. AMT Alternative Minimum Tax. COPs Certificates of Participation. ETM Escrowed to Maturity. + Prerefunded to call date shown. ++ A portion of this security has been physically segregated in connection with open futures contracts in the amount of $157,000. +++ Underlying security related to inverse floater entered into by the Trust. ++++ Floating rate note obligation related to securities held. The interest rates shown reflects the rates in effect at July 31, 2007. # Currently a zero coupon security; will convert to 5.30% on June 15, 2012. ## Currently a zero coupon security; will convert to 5.125% on December 1, 2008. * Joint exemption in locations shown. (a) The Trust invests in Morgan Stanley Institutional Liquidity Tax-Exempt Portfolio-Institutional Class, an open- end management investment company managed by the Investment Adviser. Investment advisory fees paid by the Trust are reduced by an amount equal to the advisory and administrative service fees paid by Morgan Stanley Institutional Liquidity Tax-Exempt Portfolio - Institutional Class with respect to assets invested by the Trust in Morgan Stanley Institutional Liquidity Tax-Exempt Portfolio - Institutional Class. Income distributions earned by the Trust totaled $51,491 for the period ended July 31, 2007. (b) Floating Rate Note Obligations Related to Securities Held - The Trust enters into transactions in which it transfers to Dealer Trusts ("Dealer Trusts"), fixed rate bonds in exchange for cash and residual interests in the Dealer Trusts' assets and cash flows, which are in the form of inverse floating rate investments. The Dealer Trusts fund the purchases of the fixed rate bonds by issuing floating rate notes to third parties and allowing the Trust to retain residual interest in the bonds. The Trust enters into shortfall agreements with the Dealer Trusts which commit the Trust to pay the Dealer Trusts, in certain circumstances, the difference between the liquidation value of the fixed rate bonds held by the Dealer Trusts and the liquidation value of the floating rate notes held by third parties, as well as any shortfalls in interest cash flows. The residual interests held by the Trust (inverse floating rate investments) include the right of the Trust (1) to cause the holders of the floating rate notes to tender their notes at par at the next interest rate reset date, and (2) to transfer the municipal bond from the Dealer Trusts to the Trust, thereby collapsing the Dealer Trusts. The Trust accounts for the transfer of bonds to the Dealer Trusts as secured borrowings, with the securities transferred remaining in the Trust's investment assets, and the related floating rate notes reflected as Trust liabilities. The notes issued by the Dealer Trust have interest rates that reset weekly and the floating rate note holders have the option to tender their notes to the Dealer Trust for redemption at par at each reset date. At July 31, 2007, Trust investments with a value of $60,818,611 are held by the Dealer Trust and serve as collateral for the $45,580,000 in floating rate note obligations outstanding at that date. Contractual maturities of the floating rate note obligations and interest rates in effect at July 31, 2007 are presented in the "Portfolio of Investments". (c) Securities have been designated as collateral in an amount equal to $17,329,850 in connection with open futures contracts and an open swap contract. (d) The aggregate cost for federal income tax purposes approximates the aggregate cost for book purposes. The aggregate gross unrealized appreciation is $16,431,336 and the aggregate gross unrealized depreciation is $2,559,078, resulting in net unrealized appreciation of $13,872,258. Bond Insurance: --------------- AGC Assured Guaranty Corporation. Ambac Ambac Assurance Corporation. FGIC Financial Guaranty Insurance Company. FSA Financial Security Assurance Inc. MBIA Municipal Bond Investors Assurance Corporation. XLCA XL Capital Assurance Inc. FUTURES CONTRACTS OPEN AT JULY 31, 2007: NUMBER OF DESCRIPTION, DELIVERY UNDERLYING FACE UNREALIZED CONTRACTS LONG/SHORT MONTH AND YEAR AMOUNT AT VALUE DEPRECIATION --------- ---------- ----------------------------- --------------- ------------ 60 Short U.S. Treasury Notes 30 Year, September 2007 $ (6,603,750) $ (5,790) 100 Short U.S. Treasury Notes 10 Year, September 2007 (10,742,188) (35,432) --------- Total Unrealized Depreciation $(41,222) ========= INTEREST RATE SWAP CONTRACT OPEN AT JULY 31, 2007: NOTIONAL AMOUNT PAYMENTS PAYMENTS TERMINATION UNREALIZED COUNTERPARTY (000) MADE BY TRUST RECEIVED BY TRUST DATE APPRECIATION ------------------------------------------------------------------------------------------------------------------------ JPMorgan Chase & Co. $20,000 Fixed Rate 3.79% Floating Rate 3.85% August 24, 2017 $181,694 ======== ITEM 2. CONTROLS AND PROCEDURES. (a) The Trust's principal executive officer and principal financial officer have concluded that the Trust's disclosure controls and procedures are sufficient to ensure that information required to be disclosed by the Trust's in this Form N-Q was recorded, processed, summarized and reported within the time periods specified in the Securities and Exchange Commission's rules and forms, based upon such officers' evaluation of these controls and procedures as of a date within 90 days of the filing date of the report. (b) There were no changes in the Trust's internal control over financial reporting that occurred during the registrant's fiscal quarter that has materially affected, or is reasonably likely to materially affect, the Trust'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 are attached hereto. 2 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. Morgan Stanley Insured Municipal Income Trust /s/ Ronald E. Robison Ronald E. Robison Principal Executive Officer September 20, 2007 Pursuant to the requirements of the Securities Exchange Act of 1934 and the Investment Company Act of 1940, this report has been signed by the following persons on behalf of the registrant and in the capacities and on the dates indicated. /s/ Ronald E. Robison Ronald E. Robison Principal Executive Officer September 20, 2007 /s/ Francis Smith Francis Smith Principal Financial Officer September 20, 2007 3 EXHIBIT 3 A1 CERTIFICATION OF PRINCIPAL EXECUTIVE OFFICER I, Ronald E. Robison, certify that: 1. I have reviewed this report on Form N-Q of Morgan Stanley Insured Municipal Income Trust; 2. Based on my knowledge, this report does not contain any untrue statement of a material fact or omit to state a material fact necessary to make the statements made, in light of the circumstances under which such statements were made, not misleading with respect to the period covered by this report; 3. Based on my knowledge, the schedules of investments included in this report fairly present in all material respects the investments of the registrant as of the end of the fiscal quarter for which the report is filed; 4. The registrant's other certifying officer(s) and I are responsible for establishing and maintaining disclosure controls and procedures (as defined in Rule 30a-3(c) under the Investment Company Act of 1940) for the registrant and have: (a) Designed such disclosure controls and procedures, or caused such disclosure controls and procedures to be designed under our supervision, to ensure that material information relating to the registrant, including its consolidated subsidiaries, is made known to us by others within those entities, particularly during the period in which this report is being prepared; (b) Omitted; (c) Evaluated the effectiveness of the registrant's disclosure controls and procedures and presented in this report our conclusions about the effectiveness of the disclosure controls and procedures, as of a date within 90 days prior to the filing date of this report, based on such evaluation; and (d) Disclosed in this report any change in the registrant's internal control over financial reporting that occurred during the second fiscal quarter of the period covered by this report that has materially affected, or is reasonably likely to materially affect, the registrant's internal control over financial reporting; and 5. The registrant's other certifying officer(s) and I have disclosed to the registrant's auditors and the audit committee of the registrant's board of directors (or persons performing the equivalent functions): (a) All significant deficiencies and material weaknesses in the design or operation of internal control over financial reporting which are reasonably likely to adversely affect the registrant's ability to record, process, summarize, and report financial information; and (b) Any fraud, whether or not material, that involves management or other employees who have a significant role in the registrant's internal control over financial reporting. Date: September 20, 2007 /s/ Ronald E. Robison Ronald E. Robison Principal Executive Officer 4 EXHIBIT 3 A2 CERTIFICATION OF PRINCIPAL FINANCIAL OFFICER I, Francis Smith, certify that: 1. I have reviewed this report on Form N-Q of Morgan Stanley Insured Municipal Income Trust; 2. Based on my knowledge, this report does not contain any untrue statement of a material fact or omit to state a material fact necessary to make the statements made, in light of the circumstances under which such statements were made, not misleading with respect to the period covered by this report; 3. Based on my knowledge, the schedules of investments included in this report fairly present in all material respects the investments of the registrant as of the end of the fiscal quarter for which the report is filed; 4. The registrant's other certifying officer(s) and I are responsible for establishing and maintaining disclosure controls and procedures (as defined in Rule 30a-3(c) under the Investment Company Act of 1940) for the registrant and have: (a) Designed such disclosure controls and procedures, or caused such disclosure controls and procedures to be designed under our supervision, to ensure that material information relating to the registrant, including its consolidated subsidiaries, is made known to us by others within those entities, particularly during the period in which this report is being prepared; (b) Omitted; (c) Evaluated the effectiveness of the registrant's disclosure controls and procedures and presented in this report our conclusions about the effectiveness of the disclosure controls and procedures, as of a date within 90 days prior to the filing date of this report, based on such evaluation; and (d) Disclosed in this report any change in the registrant's internal control over financial reporting that occurred during the registrant's most recent fiscal quarter that has materially affected, or is reasonably likely to materially affect, the registrant's internal control over financial reporting; and 5. The registrant's other certifying officer(s) and I have disclosed to the registrant's auditors and the audit committee of the registrant's board of directors (or persons performing the equivalent functions): (a) All significant deficiencies and material weaknesses in the design or operation of internal control over financial reporting which are reasonably likely to adversely affect the registrant's ability to record, process, summarize, and report financial information; and (b) Any fraud, whether or not material, that involves management or other employees who have a significant role in the registrant's internal control over financial reporting. Date: September 20, 2007 /s/ Francis Smith Francis Smith Principal Financial Officer 5