- Annual report of proxy voting record for management investment companies (N-PX)

UNITED STATES
SECURITIES AND EXCHANGE COMMISSION
Washington, D.C. 20549

FORM N-PX
ANNUAL REPORT OF PROXY VOTING RECORD 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)

Terrence J. Cullen
60 State Street
Boston, MA 02109
(Name and address of agent for service)

Registrant's telephone number, including area code: [phone]

Date of fiscal year end: April 30

Date of reporting period: July 1, 2009 to June 30, 2010

SIGNATURES

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.

(Registrant) Pioneer Municipal High Income Trust

By (Signature and Title) /s/ John F. Cogan, Jr. ------------------------- John F. Cogan, Jr., Chairman and President

Date August 19, 2010

===================== PIONEER MUNICIPAL HIGH INCOME TRUST ======================

DELTA AIR LINES, INC.

Ticker: DAL Security ID: 247361702 Meeting Date: JUN 30, 2010 Meeting Type: Annual Record Date: MAY 3, 2010 # Proposal Mgt Rec Vote Cast Sponsor 1 Elect Director Richard H. Anderson For For Management 2 Elect Director Edward H. Bastian For For Management 3 Elect Director Roy J. Bostock For For Management 4 Elect Director John S. Brinzo For For Management 5 Elect Director Daniel A. Carp For For Management 6 Elect Director John M. Engler For For Management 7 Elect Director Mickey P. Foret For For Management 8 Elect Director David R. Goode For For Management 9 Elect Director Paula Rosput Reynolds For For Management 10 Elect Director Kenneth C. Rogers For For Management 11 Elect Director Rodney E. Slater For For Management 12 Elect Director Douglas M. Steenland For For Management 13 Elect Director Kenneth B. Woodrow For For Management 14 Ratify Auditors For For Management 15 Provide for Cumulative Voting Against For Shareholder

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VALLEY HEALTH SYSTEM CALIF HOSP

Ticker: Security ID: 919676AF3
Meeting Date: JAN 22, 2010 Meeting Type: Written Consent
Record Date:

# Proposal Mgt Rec Vote Cast Sponsor
1 The Plan None For Management

========== END NPX REPORT