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: 811-05597 Morgan Stanley Municipal Income Opportunities Trust (Exact name of registrant as specified in charter) 1221 Avenue of the Americas, New York, New York 10020 (Address of principal executive offices) (Zip code) Ronald E. Robison 1221 Avenue of the Americas, New York, New York 10020 (Name and address of agent for service) Registrant's telephone number, including area code: 212-762-4000 Date of fiscal year end: May 31, 2007 Date of reporting period: August 31, 2006 ITEM 1. SCHEDULE OF INVESTMENTS. The Fund'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 MUNICIPAL INCOME OPPORTUNITIES TRUST PORTFOLIO OF INVESTMENTS AUGUST 31, 2006 (UNAUDITED) PRINCIPAL AMOUNT IN COUPON MATURITY THOUSANDS RATE DATE VALUE --------- ------ -------- ------------ TAX-EXEMPT MUNICIPAL BONDS (96.2%) Educational Facilities Revenue (3.2%) $ 985 Bellalago Educational Facilities Benefits District, Florida, 5.80% 05/01/34 $ 1,021,327 Bellalago Charter School Ser 2004 B 500 Illinois Finance Authority, Fullerton Village Student Housing 5.125 06/01/35 504,895 Ser 2004 A 500 Maryland Industrial Development Financing Authority, Our Lady of 6.00 05/01/35 533,510 Good Counsel High School Ser 2005 A 1,000 Westchester County Industrial Development Agency, New York, 5.375 08/01/24 1,042,100 Guiding Eyes for The Blind Inc Ser 2004 2,000 Chattanooga Health Educational & Housing Facilities Board, Tennessee, Student Housing Refg Ser 2005 A 5.125 10/01/35 2,006,400 -------- ------------ 4,985 5,108,232 -------- ------------ Hospital Revenue (12.6%) 1,000 Colbert County - Northwest Health Care Authority, Alabama, Helen 5.75 06/01/27 1,042,070 Keller Hospital Ser 2003 2,000 Baxter County, Arkansas, Baxter County Regional Hospital Impr & 5.625 09/01/28 2,052,620 Refg Ser 1999 B 2,000 Hawaii Department of Budget & Finance, Kuakini Health 2002 Ser A 6.375 07/01/32 2,184,480 1,000 Indiana Health Facility Financing Authority, Riverview Hospital 6.125 08/01/31 1,076,920 Ser 2002 500 Maryland Health & Higher Education Facilities Authority, General 5.40 01/01/31 518,775 German Aged People's Home of Baltimore, Ser 2006 A 600 Gaylord Hospital Financing Authority, Michigan, Otsego Memorial 6.50 01/01/37 622,890 Hospital Ser 2004 1,500 St Paul, Housing & Redevelopment Authority, Minnesota, 6.00 11/15/35 1,648,470 HealthEast Ser 2005 2,335 Henderson, Nevada, Catholic Health West 1998 Ser A 5.375 07/01/26 2,390,690 1,500 New Hampshire Higher Educational & Health Facilities Authority, 6.00 05/01/28 1,535,955 Littleton Hospital Association Ser 1998 A 2,000 New Jersey Health Care Facilities Financing Authority, Raritan Bay 7.25 07/01/27 2,046,400 Medical Center Ser 1994 955 Nassau County Industrial Development Agency, New York, North 5.875 11/01/11 1,000,964 Shore Health Ser B 500 Fulton County Industrial Development Authority, Pennsylvania, 5.875 07/01/31 511,385 Fulton County Medical Center Ser 2006 1,000 Monroe County Hospital Authority, Pennsylvania, Pocono Medical 6.00 01/01/43 1,068,910 Center Ser 2003 285 South Carolina Jobs Economic Development Authority, Palmetto 6.875 08/01/27 328,953 Health Alliance Refg Ser 2003 C 1,000 Knox County Health, Educational & Housing Facility Board, 6.50 04/15/31 1,099,040 Tennessee, Baptist Health of East Tennessee Ser 2002 1,000 Decatur Hospital Authority, Texas, Wise Regional Health Ser 2004 A 7.125 09/01/34 1,094,900 -------- ------------ 19,175 20,223,422 -------- ------------ Industrial Development/Pollution Control Revenue (12.2%) 1,000 Northern Tobacco Securitization Corporation, Alaska, Ser 2006 A 5.00 06/01/46 987,160 2,000 California County Tobacco Securitization Agency, Gold County 0.00 06/01/33 430,140 Settlement Funding Corp Ser 2006 (WI) 260 Metropolitan Washington Airports Authority, District of Columbia & 10.125 09/01/11 260,377 Virginia, CaterAir International Corp Ser 1991 (AMT) ++ 1,500 Iowa Finance Authority, IPSCO Inc Ser 1997 (AMT) 6.00 06/01/27 1,513,035 1,000 Nassau County Tobacco Settlement Corporation, New York, 5.125 06/01/46 1,007,550 Ser 2006 A-3 New York City Industrial Development Agency, New York, 2,000 7 World Trade Center LLC Ser A 6.50 03/01/35 2,138,400 2,000 American Airlines Inc Ser 2005 (AMT) 7.75 08/01/31 2,320,300 1,500 TSASC Inc, New York, Tobacco Settlement Ser 2006-1 5.125 06/01/42 1,510,755 325 Zanesville-Muskingum County Port Authority, Ohio, Anchor Glass 10.25 12/01/08 325,189 Container Corp Ser 1989 B (AMT) 2,620 Carbon County Industrial Development Authority, Pennsylvania, 6.65 05/01/10 2,766,824 Panther Creek Partners Refg 2000 Ser (AMT) 1,000 Pennsylvania Economic Development Financing Authority, Reliant 6.75 12/01/36 1,074,210 Energy Inc Ser 2001 A (AMT) 350 Lexington County, South Carolina, Ellett Brothers Inc Refg Ser 1988 7.50 09/01/08 347,652 1,000 Brazos River Authority, Texas, Texas Utilities Electric Co Refg 7.70 04/01/33 1,169,300 Ser 1999 A (AMT) 1,000 Chesterfield County Industrial Development Authority, Virginia, 5.50 10/01/09 1,012,550 Virginia Electric & Power Co Ser 1985 2,700 Pittsylvania County Industrial Development Authority, Virginia, Multi-Trade LP Ser 1994 A (AMT) 7.45 01/01/09 2,706,723 -------- ------------ 20,255 19,570,165 -------- ------------ Mortgage Revenue - Multi-Family (7.9%) Washington County Housing & Redevelopment Authority, Minnesota, 3,885 Courtly Park Ser 1989 A 9.75 06/15/19 3,528,474 1,165 Courtly Park Ser 1989 A (AMT) 10.25 06/15/19 1,057,773 8,678 Courtly Park Ser 1989 B (AMT) 0.00 06/15/19 209,137 24,080 Courtly Park Ser 1989 B 0.00 06/15/19 580,327 White Bear Lake, Minnesota, 3,715 White Bear Woods Apts Phase II Refg 1989 Ser A 9.75 06/15/19 3,561,050 19,771 White Bear Woods Apts Phase II Refg 1989 Ser B 0.00 06/15/19 604,017 3,000 Brookhaven Industrial Development Agency, New York, Woodcrest Estates Ser 1998 A (AMT) 6.375 12/01/37 3,064,950 -------- ------------ 64,294 12,605,728 -------- ------------ Mortgage Revenue - Single Family (5.0%) Colorado Housing & Finance Authority, 85 1996 Ser B (AMT) 7.65 11/01/26 86,489 530 Ser 1998 D-2 (AMT) 6.35 11/01/29 535,592 17,360 New Hampshire Housing Finance Authority, Residential 1983 Ser B 0.00 01/01/15 7,367,063 -------- ------------ 17,975 7,989,144 -------- ------------ Nursing & Health Related Facilities Revenue (9.0%) Escambia County, Florida, 4,250 Pensacola Care Development Centers Ser 1989 10.25 07/01/11 4,303,763 980 Pensacola Care Development Centers Ser 1989 A 10.25 07/01/11 992,397 1,000 Orange County Health Facilities Authority, Florida, Westminister 6.75 04/01/34 1,039,400 Community Care Services Inc Ser 1999 1,000 Pinellas County Health Facilities Authority, Florida, Oaks of 6.25 06/01/34 1,063,950 Clearwater Ser 2004 525 Washington County Hospital, Iowa, Ser 2006 5.375 07/01/26 538,466 515 Kentucky Economic Development Financing Authority, 6.50# 01/01/29 555,597 AHF/Kentucky-Iowa Inc Ser 2003 1,725 Massachusetts Development Finance Agency, New England Center 5.875 11/01/18 1,766,038 for Children Ser 1998 1,000 Massachusetts Health & Educational Facilities Authority, The 6.125 07/01/29 1,020,180 Learning Center for Deaf Children Ser C 1,000 St Louis County Industrial Development Authority, Missouri, 6.625 11/15/35 1,038,680 Pediatric Rehabilitation Center Ser 2003 A 610 Mount Vernon Industrial Development Agency, New York, 6.00 06/01/09 622,926 Meadowview at the Wartburg Ser 1999 1,500 Suffolk County Industrial Development Agency, New York, Medford Hamlet Ser 2006 6.375 01/01/39 1,515,870 -------- ------------ 14,105 14,457,267 -------- ------------ Recreational Facilities Revenue (4.5%) 2,000 Sacramento Financing Authority, California, Convention Center 6.25 01/01/30 2,100,440 Hotel 1999 Ser A 1,000 San Diego County, California, San Diego Natural History Museum 5.70 02/01/28 1,003,380 COPs 1,000 Mashantucket (Western) Pequot Tribe, Connecticut, Special 1997 5.75 09/01/27 1,024,990 Ser B (a) 1,000 New York Liberty Development Corp, National Sports Museum, 6.125 02/15/19 1,033,290 Ser 2006 A 2,000 Austin Convention Enterprises Inc, Texas, Convention Center Hotel Ser 2000 A 6.70 01/01/32 2,118,060 -------- ------------ 7,000 7,280,160 -------- ------------ Retirement & Life Care Facilities Revenue (20.7%) 500 Orange County Health Facilities Authority, Florida, Orlando 5.70 07/01/26 513,250 Lutheran Towers Inc Ser 2005** 1,000 St Johns County Industrial Development Authority, Florida, 8.00 01/01/30 1,071,520 Glenmoor Ser 1999 A 1,000 Hawaii Department of Budget & Finance, Kahala Nui 2003 Ser A 8.00 11/15/33 1,158,150 Illinois Finance Authority, 1,000 Landing at Plymouth Place Ser 2005 A 6.00 05/15/37 1,038,490 1,000 Luther Oaks Ser 2006 A 6.00 08/15/39 1,031,410 1,500 Lenexa, Kansas, Lakeview Village - Southridge Ser 2002 C 6.875 05/15/32 1,624,830 1,500 Maryland Health & Higher Educational Facilities Authority, Mercy 6.00 04/01/35 1,587,810 Ridge 2003 Ser A 1,500 Massachusetts Development Finance Agency, Loomis Communities 5.75 07/01/23 1,544,100 Ser 1999 A 1,500 Kansas City Industrial Development Agency, Missouri, Bishop 6.50 01/01/35 1,583,670 Spencer 2004 Ser A New Jersey Economic Development Authority, 1,000 Cedar Crest Village Inc Ser 2001 A 7.25 11/15/31 1,087,980 1,000 Franciscan Oaks Ser 1997 5.70 10/01/17 1,024,580 730 Lions Gate Ser 2005 A 5.875 01/01/37 751,878 1,000 The Presbyterian Home at Montgomery Ser 2001 A 6.375 11/01/31 1,060,140 2,000 United Methodist Homes of New Jersey Ser 1998 5.125 07/01/25 1,937,640 750 Suffolk County Industrial Development Agency, New York, 5.00 11/01/28 769,500 Jefferson's Ferry Ser 2006 (WI) 1,000 North Carolina Medical Care Commission, Presbyterian Homes Inc 5.50 10/01/31 1,032,770 Ser 2006 1,000 North Carolina Medical Care Commission, Given Estate Ser 2003 A 6.50 07/01/32 1,076,610 1,500 Bucks County Industrial Development Authority, Pennsylvania, 6.125 01/01/25 1,604,865 Ann's Choice Ser 2005 A 1,000 Chester County Health & Education Facilities Authority, 7.625 07/01/34 1,133,830 Pennsylvania, Jenner's Pond Inc Ser 2002 1,000 Montgomery County Industry Development Authority, Pennsylvania, 6.25 02/01/35 1,063,080 Whitemarsh Community Ser 2005 Shelby County Health, Educational & Housing Facilities Board, Tennessee, 500 Trezevant Manor Ser 2006 A 5.75 09/01/37 502,870 500 Village at Germantown Ser 2006 6.25 12/01/34 507,115 750 Village at Germantown Ser 2003 A 7.25 12/01/34 799,290 1,000 Houston Health Facilities Authority, Texas, 7.125 02/15/34 1,112,520 Buckingham Senior Living Community Ser 2004 A 1,000 Lubbock, Health Facilities Development Corporation, Texas, Carillon 6.50 07/01/26 1,031,270 Senior Lifecare Ser 2005 A 2,100 Vermont Economic Development Authority, Wake Robin Corp 6.75 03/01/29 2,277,029 Ser 1999 A 2,000 Peninsula Ports Authority of Virginia, Virginia Baptist Homes 5.40 12/01/33+ 2,044,060 Ser 2003 A 1,000 Virginia Beach Development Authority, Virginia, Westminster- Canterbury Refg Ser 2005 A 5.25 11/01/26 1,019,980 -------- ------------ 31,330 32,990,237 -------- ------------ Tax Allocation Revenue (14.5%) 495 Carlsbad Assessment District No 2002-2001, California, Poinsettia 5.20 09/02/35 499,188 Lane East Ser 2005 A 1,000 San Marcos Community Facilities District # 2002-01, California, 5.95 09/01/35 1,045,300 University Commons Ser 2004 1,000 Santa Ana, Unified School District Community Facilities, 5.10 09/01/35 1,004,660 District # 2004-1, California, Central Park Ser 2005 1,000 Poway Unified School District, California, Community Facilities 5.25 09/01/36 1,016,730 District No 14 Ser 2006 2,000 Elk Valley Public Improvement Corporation, Colorado, Ser 2001 A 7.35 09/01/31 2,132,800 2,000 Northwest Metropolitan District #3, Colorado, Ser 2005 6.25 12/01/35 2,117,080 1,000 Southlands Metropolitan District #1, Colorado, Ser 2004 7.125 12/01/34 1,104,750 2,000 Beacon Lakes, Community Development District, Florida, Ser 2003 A 6.90 05/01/35 2,184,020 1,000 Renaissance Commons Community Development District, Florida, 5.60 05/01/36 1,029,300 2005 Ser A 1,000 Midtown Miami Community Development District, Florida, Parking 6.25 05/01/37 1,091,010 Garage Ser 2004 A 2,000 Atlanta, Georgia, Eastside Ser 2005 B 5.60 01/01/30 2,061,220 1,000 Bolingbrook, Illinois, Sales Tax Ser 2005 0.00# 01/01/24 960,200 2,000 Chicago, Illinois, Lake Shore East Ser 2002 6.75 12/01/32 2,162,640 725 Lincolnshire, Illinois, Service Area No 1-Sedgebrook Ser 2004 6.25 03/01/34 770,697 2,000 Des Peres, Missouri, West County Center Ser 2002 5.75 04/15/20 2,052,400 1,980 Las Vegas District # 808, Nevada, Summerlin Ser 2001 6.75 06/01/21 2,051,359 -------- ------------ 22,200 23,283,354 -------- ------------ Transportation Facilities Revenue (1.6%) 1,515 Mid-Bay Bridge Authority, Florida, Sr Lien Crossover Refg 5.85 10/01/13 1,603,885 Ser 1993 A (Ambac) 1,000 Nevada Department of Business & Industry, Las Vegas Monorail 2nd Tier Ser 2000 7.375 01/01/40 1,026,390 -------- ------------ 2,515 2,630,275 -------- ------------ Refunded (5.0%) 3,850 Fenton, Missouri, Gravois Bluffs Redevelopment Ser 2001 A Refg 7.00 10/01/11+ 4,464,652 3,250 Suffolk County Industrial Development Agency, New York, Jefferson's Ferry Ser 1999 7.25 11/01/09+ 3,628,138 -------- ------------ 7,100 8,092,790 -------- ------------ 210,934 TOTAL TAX-EXEMPT MUNICIPAL BONDS (Cost $159,189,198) 154,230,774 -------- ------------ TAXABLE CONVERTIBLE BOND (0.4%) Airlines 633 UAL Corp (Cost $633,081) (b) 5.00 02/01/21 576,229 -------- ------------ SHORT-TERM TAX-EXEMPT MUNICIPAL OBLIGATIONS (1.3%) 1,700 Cuyahoga County Hospital, Ohio, Ser B (Demand 09/01/06) 3.95* 01/01/16 1,700,000 445 Wisconsin Health & Educational Facilities Ser B (Demand 09/05/06) 3.30* 05/01/33 445,000 -------- ------------ 2,145 TOTAL SHORT-TERM TAX-EXEMPT MUNICIPAL OBLIGATIONS (Cost $2,145,000) 2,145,000 -------- ------------ $213,712 TOTAL INVESTMENTS (Cost $161,967,279)(c) (d) 97.9% 156,952,003 ======== OTHER ASSETS IN EXCESS OF LIABILITIES 2.1 3,356,214 -------- ------------ NET ASSETS 100.0% $160,308,217 ======== ============ ---------- AMT Alternative Minimum Tax. COPs Certificates of Participation. WI Security purchased on a when-issued basis. * Current coupon of variable rate demand obligation. ** A portion of this security is physically segregated in connection with open futures contracts in the amount of $28,000. + Prerefunded to call date shown. ++ Joint exemption in locations shown. # Security is a "step-up" bond where the coupon increases on a predetermined future date. (a) Resale is restricted to qualified institutional investors. (b) Taxable convertible bond issued in reorganization. (c) Securities have been designated as collateral in an amount equal to $6,232,625 in connection with open futures contracts and the purchase of when-issued securities. (d) The aggregate cost for federal income tax purposes approximates the aggregate cost for book purposes. The aggregate gross unrealized appreciation is $8,487,485 and the aggregate gross unrealized depreciation is $13,502,761, resulting in net unrealized Depreciation of $5,015,276. Bond Insurance: Ambac Ambac Assurance Corporation. FUTURES CONTRACTS OPEN AT AUGUST 31, 2006: NUMBER OF DESCRIPTION, DELIVERY UNDERLYING FACE UNREALIZED CONTRACTS LONG/SHORT MONTH AND YEAR AMOUNT AT VALUE DEPRECIATION --------- ---------- -------------------------------- --------------- ------------ 20 Short U.S. Treasury Note 10 Year September 2006 .............. $(2,148,438) $(43,805) 40 Short U.S. Treasury Note 5 Year September 2006 .............. (4,200,625) (44,798) -------- Total Unrealized Depreciation .. $(88,603) ======== GEOGRAPHIC SUMMARY OF INVESTMENTS Based on Market Value as a Percent of Total Investments Alabama $ 1,042,070 0.7% Alaska 987,160 0.6 Arkansas 2,052,620 1.3 California 7,099,838 4.5 Colorado 5,976,711 3.8 Connecticut 1,024,990 0.7 District of Columbia 260,377 0.2 Florida 15,913,822 10.1 Georgia 2,061,220 1.3 Hawaii 3,342,630 2.1 Illinois 7,044,561 4.5 Indiana 1,076,920 0.7 Iowa 2,051,501 1.3 Kansas 1,624,830 1.0 Kentucky 555,597 0.4 Maryland 2,640,095 1.7 Massachusetts 4,330,318 2.8 Michigan 622,890 0.4 Minnesota 11,189,248 7.1 Missouri 9,139,402 5.8 Nevada 5,468,439 3.5 New Hampshire 8,903,018 5.7 New Jersey 7,908,618 5.0 New York 19,654,743 12.5 North Carolina 2,109,380 1.3 Ohio 2,025,189 1.3 Pennsylvania 9,223,104 5.9 South Carolina 676,605 0.4 Tennessee 4,914,715 3.1 Texas 6,526,050 4.2 Vermont 2,277,029 1.5 Virginia 7,043,690 4.5 Wisconsin 445,000 0.3 Joint Exemptions* (260,377) (0.2) ------------ ----- Total $156,952,003 100.0% ============ ===== ---------- * Joint Exemptions have been included in each geographic location. + Does not include open short futures contracts with an underlying face amount of $6,349,063 with unrealized depreciation of $88,603. ITEM 2. CONTROLS AND PROCEDURES. (a) The Fund's principal executive officer and principal financial officer have concluded that the Fund's disclosure controls and procedures are sufficient to ensure that information required to be disclosed by the Fund 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 Fund'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 Fund'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 Municipal Income Opportunities Trust /s/ Ronald E. Robison ------------------------------------- Ronald E. Robison Principal Executive Officer October 19, 2006 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 October 19, 2006 /s/ Francis Smith ------------------------------------- Francis Smith Principal Financial Officer October 19, 2006 3