UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 FORM N-PX ANNUAL REPORT OF PROXY VOTING RECORD OF REGISTERED MANAGEMENT INVESTMENT COMPANY Investment Company Act file number 811-10333 Name of Fund: BlackRock Municipal Income Investment Trust (BBF) Fund Address: 100 Bellevue Parkway, Wilmington, DE 19809 Name and address of agent for service: Anne Ackerley, Chief Executive Officer, BlackRock Municipal Income Investment Trust, 40 East 52(nd) Street, New York City, NY 10022. Registrant's telephone number, including area code: (800) 882-0052, Option 4 Date of fiscal year end: 07/31 Date of reporting period: 07/01/2008 -- 06/30/2009 Item 1 -- Proxy Voting Record -- Attached hereto. Pursuant to the requirements of 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. BlackRock Municipal Income Investment Trust By: /s/ Anne Ackerley Anne Ackerley Chief Executive Officer of BlackRock Municipal Income Investment Trust Date: August 14, 2009 ******************************* FORM N-Px REPORT ******************************* ICA File Number: 811-10333 Reporting Period: 07/01/2008 - 06/30/2009 BlackRock Municipal Income Investment Trust ================= BLACKROCK MUNICIPAL INCOME INVESTMENT TRUST ================== BLACKROCK CORPORATE HIGH YIELD FUND VI INC Ticker: HYT Security ID: 09255P107 Meeting Date: SEP 12, 2008 Meeting Type: Annual Record Date: JUL 14, 2008 # Proposal Mgt Rec Vote Cast Sponsor 1.1 Elect Director G.N. Beckwith, III For For Management 1.2 Elect Director Kent Dixon For For Management 1.3 Elect Director R. Glenn Hubbard For For Management 1.4 Elect Director W. Carl Kester For For Management 1.5 Elect Director Robert S. Salomon, Jr. For For Management 1.6 Elect Director Richard S. Davis For For Management 1.7 Elect Director Frank J. Fabozzi For For Management 1.8 Elect Director James T. Flynn For For Management 1.9 Elect Director Karen P. Robards For For Management 1.10 Elect Director Richard E. Cavanagh For For Management 1.11 Elect Director Kathleen F. Feldstein For For Management 1.12 Elect Director Henry Gabbay For For Management 1.13 Elect Director Jerrold B. Harris For For Management -------------------------------------------------------------------------------- BLACKROCK ENHANCED DIVIDEND ACHIEVERS TRUST Ticker: BDJ Security ID: 09251A104 Meeting Date: SEP 12, 2008 Meeting Type: Annual Record Date: JUL 14, 2008 # Proposal Mgt Rec Vote Cast Sponsor 1.1 Elect Director G.N. Beckwith, III For For Management 1.2 Elect Director Kent Dixon For For Management 1.3 Elect Director R. Glenn Hubbard For For Management 1.4 Elect Director W. Carl Kester For For Management 1.5 Elect Director Robert S. Salomon, Jr. For For Management -------------------------------------------------------------------------------- BLACKROCK GLOBAL ENERGY AND RESOURCES TRUST Ticker: BGR Security ID: 09250U101 Meeting Date: SEP 12, 2008 Meeting Type: Annual Record Date: JUL 14, 2008 # Proposal Mgt Rec Vote Cast Sponsor 1.1 Elect Director G.N. Beckwith, III For For Management 1.2 Elect Director Kent Dixon For For Management 1.3 Elect Director R. Glenn Hubbard For For Management 1.4 Elect Director W. Carl Kester For For Management 1.5 Elect Director Robert S. Salomon, Jr. For For Management -------------------------------------------------------------------------------- BLACKROCK GLOBAL FLOATING RATE INCOME TRUST Ticker: BGT Security ID: 091941104 Meeting Date: SEP 12, 2008 Meeting Type: Annual Record Date: JUL 14, 2008 # Proposal Mgt Rec Vote Cast Sponsor 1.1 Elect Director G.N. Beckwith, III For For Management 1.2 Elect Director Kent Dixon For For Management 1.3 Elect Director R. Glenn Hubbard For For Management 1.4 Elect Director Robert S. Salomon, Jr. For For Management -------------------------------------------------------------------------------- BLACKROCK INTERNATIONAL GROWTH AND INCOME TRUST Ticker: BGY Security ID: 092524107 Meeting Date: SEP 12, 2008 Meeting Type: Annual Record Date: JUL 14, 2008 # Proposal Mgt Rec Vote Cast Sponsor 1.1 Elect Director G.N. Beckwith, III For For Management 1.2 Elect Director Kent Dixon For For Management 1.3 Elect Director R. Glenn Hubbard For For Management 1.4 Elect Director W. Carl Kester For For Management 1.5 Elect Director Robert S. Salomon, Jr. For For Management -------------------------------------------------------------------------------- BLACKROCK LIMITED DURATION INCOME TRUST Ticker: BLW Security ID: 09249W101 Meeting Date: SEP 12, 2008 Meeting Type: Annual Record Date: JUL 14, 2008 # Proposal Mgt Rec Vote Cast Sponsor 1.1 Elect Director G.N. Beckwith, III For For Management 1.2 Elect Director Kent Dixon For For Management 1.3 Elect Director R. Glenn Hubbard For For Management 1.4 Elect Director W. Carl Kester For For Management 1.5 Elect Director Robert S. Salomon, Jr. For For Management -------------------------------------------------------------------------------- BLACKROCK PREFERRED & EQUITY ADVANTAGE TRUST Ticker: BTZ Security ID: 092508100 Meeting Date: SEP 12, 2008 Meeting Type: Annual Record Date: JUL 14, 2008 # Proposal Mgt Rec Vote Cast Sponsor 1.1 Elect Director G.N. Beckwith, III For For Management 1.2 Elect Director Kent Dixon For For Management 1.3 Elect Director R. Glenn Hubbard For For Management 1.4 Elect Director Robert S. Salomon, Jr. For For Management -------------------------------------------------------------------------------- BLACKROCK PREFERRED INCOME STRATEGIES FUND INC Ticker: PSY Security ID: 09255H105 Meeting Date: SEP 12, 2008 Meeting Type: Annual Record Date: JUL 14, 2008 # Proposal Mgt Rec Vote Cast Sponsor 1.1 Elect Director G.N. Beckwith, III For For Management 1.2 Elect Director Kent Dixon For For Management 1.3 Elect Director R. Glenn Hubbard For For Management 1.4 Elect Director Robert S. Salomon, Jr. For For Management 1.5 Elect Director Richard S. Davis For For Management 1.6 Elect Director James T. Flynn For For Management 1.7 Elect Director Karen P. Robards For For Management 1.8 Elect Director Richard E. Cavanagh For For Management 1.9 Elect Director Kathleen F. Feldstein For For Management 1.10 Elect Director Henry Gabbay For For Management 1.11 Elect Director Jerrold B. Harris For For Management ========== END NPX REPORT