-----BEGIN PRIVACY-ENHANCED MESSAGE-----
Proc-Type: 2001,MIC-CLEAR
Originator-Name: webmaster@www.sec.gov
Originator-Key-Asymmetric:
 MFgwCgYEVQgBAQICAf8DSgAwRwJAW2sNKK9AVtBzYZmr6aGjlWyK3XmZv3dTINen
 TWSM7vrzLADbmYQaionwg5sDW3P6oaM5D3tdezXMm7z1T+B+twIDAQAB
MIC-Info: RSA-MD5,RSA,
 I/d5D0DUgaoDVAuocva+c7jIgbdJG5fj4kKfJzFfHdR/UA/Os8ijS/NX3An+P39k
 MEOu40yrOM7oKiTZUG8Wlg==

<SEC-DOCUMENT>0001198272-08-000051.txt : 20080226
<SEC-HEADER>0001198272-08-000051.hdr.sgml : 20080226
<ACCEPTANCE-DATETIME>20080226134137
ACCESSION NUMBER:		0001198272-08-000051
CONFORMED SUBMISSION TYPE:	4
PUBLIC DOCUMENT COUNT:		1
CONFORMED PERIOD OF REPORT:	20080225
FILED AS OF DATE:		20080226
DATE AS OF CHANGE:		20080226

ISSUER:		

	COMPANY DATA:	
		COMPANY CONFORMED NAME:			PUTNAM INVESTMENT GRADE MUNICIPAL TRUST
		CENTRAL INDEX KEY:			0000855048
		STANDARD INDUSTRIAL CLASSIFICATION:	UNKNOWN SIC - 0000 [0000]
		IRS NUMBER:				046629611
		STATE OF INCORPORATION:			MA
		FISCAL YEAR END:			1231

	BUSINESS ADDRESS:	
		STREET 1:		ONE POST OFFICE SQUARE
		CITY:			BOSTON
		STATE:			MA
		ZIP:			02109
		BUSINESS PHONE:		6172921000

	MAIL ADDRESS:	
		STREET 1:		ONE POST OFFICE SQU
		CITY:			BOSTON
		STATE:			MA
		ZIP:			02109

REPORTING-OWNER:	

	OWNER DATA:	
		COMPANY CONFORMED NAME:			CURTIS B CHARLES
		CENTRAL INDEX KEY:			0001198272

	FILING VALUES:
		FORM TYPE:		4
		SEC ACT:		1934 Act
		SEC FILE NUMBER:	811-05901
		FILM NUMBER:		08642266

	MAIL ADDRESS:	
		STREET 1:		C/O PUTNAM LLC
		STREET 2:		ONE POST OFFICE SQUARE L5
		CITY:			BOSTON
		STATE:			MA
		ZIP:			02109
</SEC-HEADER>
<DOCUMENT>
<TYPE>4
<SEQUENCE>1
<FILENAME>primary_doc.xml
<DESCRIPTION>PRIMARY DOCUMENT
<TEXT>
<XML>
<?xml version="1.0"?>
<ownershipDocument>

    <schemaVersion>X0202</schemaVersion>

    <documentType>4</documentType>

    <periodOfReport>2008-02-25</periodOfReport>

    <notSubjectToSection16>0</notSubjectToSection16>

    <issuer>
        <issuerCik>0000855048</issuerCik>
        <issuerName>PUTNAM INVESTMENT GRADE MUNICIPAL TRUST</issuerName>
        <issuerTradingSymbol>pgm</issuerTradingSymbol>
    </issuer>

    <reportingOwner>
        <reportingOwnerId>
            <rptOwnerCik>0001198272</rptOwnerCik>
            <rptOwnerName>CURTIS B CHARLES</rptOwnerName>
        </reportingOwnerId>
        <reportingOwnerAddress>
            <rptOwnerStreet1>C/O PUTNAM LLC</rptOwnerStreet1>
            <rptOwnerStreet2>ONE POST OFFICE SQUARE L5</rptOwnerStreet2>
            <rptOwnerCity>BOSTON</rptOwnerCity>
            <rptOwnerState>MA</rptOwnerState>
            <rptOwnerZipCode>02109</rptOwnerZipCode>
            <rptOwnerStateDescription></rptOwnerStateDescription>
        </reportingOwnerAddress>
        <reportingOwnerRelationship>
            <isDirector>1</isDirector>
            <isOfficer>0</isOfficer>
            <isTenPercentOwner>0</isTenPercentOwner>
            <isOther>0</isOther>
        </reportingOwnerRelationship>
    </reportingOwner>

    <nonDerivativeTable>
        <nonDerivativeTransaction>
            <securityTitle>
                <value>Common shares</value>
            </securityTitle>
            <transactionDate>
                <value>2008-02-25</value>
                <footnoteId id="F1"/>
            </transactionDate>
            <transactionCoding>
                <transactionFormType>4</transactionFormType>
                <transactionCode>J</transactionCode>
                <equitySwapInvolved>0</equitySwapInvolved>
                <footnoteId id="F2"/>
            </transactionCoding>
            <transactionTimeliness>
                <value></value>
            </transactionTimeliness>
            <transactionAmounts>
                <transactionShares>
                    <value>120.605</value>
                </transactionShares>
                <transactionPricePerShare>
                    <value>10.46</value>
                    <footnoteId id="F3"/>
                </transactionPricePerShare>
                <transactionAcquiredDisposedCode>
                    <value>D</value>
                </transactionAcquiredDisposedCode>
            </transactionAmounts>
            <postTransactionAmounts>
                <sharesOwnedFollowingTransaction>
                    <value>0</value>
                    <footnoteId id="F4"/>
                </sharesOwnedFollowingTransaction>
            </postTransactionAmounts>
            <ownershipNature>
                <directOrIndirectOwnership>
                    <value>D</value>
                </directOrIndirectOwnership>
            </ownershipNature>
        </nonDerivativeTransaction>
    </nonDerivativeTable>

    <footnotes>
        <footnote id="F1">Effective date of merger of issuer into Putnam Municipal Opportunities Trust.</footnote>
        <footnote id="F2">Issuer (PGM) merged into Putnam Municipal Opportunities Trust (PMO), a closed-end investment company, on February 25, 2008.  All outstanding PGM common shares were exchanged for common shares of PMO based on the respective per-share net asset values of each fund's common shares calculated as of February 22, 2008.</footnote>
        <footnote id="F3">Per-share net asset value of PGM common shares as of February 22, 2008.  Reflects rounding.</footnote>
        <footnote id="F4">Issuer (PGM) merged into Putnam Municipal Opportunities Trust (PMO), a closed-end investment company, on February 25, 2008.  All outstanding PGM common shares were exchanged for common shares of PMO based on the respective per-share net asset values of each fund's common shares calculated as of February 22, 2008.</footnote>
    </footnotes>

    <ownerSignature>
        <signatureName>Charles B. Curtis</signatureName>
        <signatureDate>2008-02-26</signatureDate>
    </ownerSignature>
</ownershipDocument>
</XML>
</TEXT>
</DOCUMENT>
</SEC-DOCUMENT>
-----END PRIVACY-ENHANCED MESSAGE-----