<SEC-DOCUMENT>0001140361-12-003166.txt : 20120120
<SEC-HEADER>0001140361-12-003166.hdr.sgml : 20120120
<ACCEPTANCE-DATETIME>20120120125212
ACCESSION NUMBER:		0001140361-12-003166
CONFORMED SUBMISSION TYPE:	4
PUBLIC DOCUMENT COUNT:		1
CONFORMED PERIOD OF REPORT:	20120118
FILED AS OF DATE:		20120120
DATE AS OF CHANGE:		20120120

ISSUER:		

	COMPANY DATA:	
		COMPANY CONFORMED NAME:			BLACKROCK INVESTMENT QUALITY MUNICIPAL TRUST INC
		CENTRAL INDEX KEY:			0000894242
		IRS NUMBER:				133690436
		STATE OF INCORPORATION:			MD
		FISCAL YEAR END:			1031

	BUSINESS ADDRESS:	
		STREET 1:		100 BELLEVUE PARKWAY
		STREET 2:		MUTUAL FUND DEPARTMENT
		CITY:			WILMINGTON
		STATE:			DE
		ZIP:			19809
		BUSINESS PHONE:		888-825-2257

	MAIL ADDRESS:	
		STREET 1:		100 BELLEVUE PARKWAY
		STREET 2:		MUTUAL FUND DEPARTMENT
		CITY:			WILMINGTON
		STATE:			DE
		ZIP:			19809

REPORTING-OWNER:	

	OWNER DATA:	
		COMPANY CONFORMED NAME:			BANK OF AMERICA CORP /DE/
		CENTRAL INDEX KEY:			0000070858
		STANDARD INDUSTRIAL CLASSIFICATION:	NATIONAL COMMERCIAL BANKS [6021]
		STATE OF INCORPORATION:			DE
		FISCAL YEAR END:			1231

	FILING VALUES:
		FORM TYPE:		4
		SEC ACT:		1934 Act
		SEC FILE NUMBER:	811-07354
		FILM NUMBER:		12536396

	BUSINESS ADDRESS:	
		STREET 1:		BANK OF AMERICA CORPORATE CENTER
		STREET 2:		100 N TRYON ST
		CITY:			CHARLOTTE
		STATE:			NC
		ZIP:			28255
		BUSINESS PHONE:		7043868486

	MAIL ADDRESS:	
		STREET 1:		BANK OF AMERICA CORPORATE CENTER
		STREET 2:		100 N TRYON ST
		CITY:			CHARLOTTE
		STATE:			NC
		ZIP:			28255

	FORMER NAME:	
		FORMER CONFORMED NAME:	BANKAMERICA CORP/DE/
		DATE OF NAME CHANGE:	19981022

	FORMER NAME:	
		FORMER CONFORMED NAME:	NATIONSBANK CORP
		DATE OF NAME CHANGE:	19920703

	FORMER NAME:	
		FORMER CONFORMED NAME:	NCNB CORP
		DATE OF NAME CHANGE:	19920107

REPORTING-OWNER:	

	OWNER DATA:	
		COMPANY CONFORMED NAME:			BANK OF AMERICA NA
		CENTRAL INDEX KEY:			0001102113

	FILING VALUES:
		FORM TYPE:		4
		SEC ACT:		1934 Act
		SEC FILE NUMBER:	811-07354
		FILM NUMBER:		12536395

	BUSINESS ADDRESS:	
		STREET 1:		100 N. TRYON STREET
		CITY:			CHARLOTTE
		STATE:			NC
		ZIP:			28255
		BUSINESS PHONE:		(704) 386-5494

	MAIL ADDRESS:	
		STREET 1:		100 N. TRYON STREET
		CITY:			CHARLOTTE
		STATE:			NC
		ZIP:			28255

REPORTING-OWNER:	

	OWNER DATA:	
		COMPANY CONFORMED NAME:			Blue Ridge Investments, L.L.C.
		CENTRAL INDEX KEY:			0001453700
		STATE OF INCORPORATION:			DE

	FILING VALUES:
		FORM TYPE:		4
		SEC ACT:		1934 Act
		SEC FILE NUMBER:	811-07354
		FILM NUMBER:		12536397

	BUSINESS ADDRESS:	
		STREET 1:		214 NORTH TRYON STREET
		CITY:			CHARLOTTE
		STATE:			NC
		ZIP:			28255
		BUSINESS PHONE:		980-386-4161

	MAIL ADDRESS:	
		STREET 1:		214 NORTH TRYON STREET
		CITY:			CHARLOTTE
		STATE:			NC
		ZIP:			28255
</SEC-HEADER>
<DOCUMENT>
<TYPE>4
<SEQUENCE>1
<FILENAME>doc1.xml
<DESCRIPTION>FORM 4
<TEXT>
<XML>
<?xml version="1.0"?>
<ownershipDocument>

    <schemaVersion>X0304</schemaVersion>

    <documentType>4</documentType>

    <periodOfReport>2012-01-18</periodOfReport>

    <notSubjectToSection16>1</notSubjectToSection16>

    <issuer>
        <issuerCik>0000894242</issuerCik>
        <issuerName>BLACKROCK INVESTMENT QUALITY MUNICIPAL TRUST INC</issuerName>
        <issuerTradingSymbol>BKN</issuerTradingSymbol>
    </issuer>

    <reportingOwner>
        <reportingOwnerId>
            <rptOwnerCik>0000070858</rptOwnerCik>
            <rptOwnerName>BANK OF AMERICA CORP /DE/</rptOwnerName>
        </reportingOwnerId>
        <reportingOwnerAddress>
            <rptOwnerStreet1>BANK OF AMERICA CORPORATE CENTER</rptOwnerStreet1>
            <rptOwnerStreet2>100 N TRYON ST</rptOwnerStreet2>
            <rptOwnerCity>CHARLOTTE</rptOwnerCity>
            <rptOwnerState>NC</rptOwnerState>
            <rptOwnerZipCode>28255</rptOwnerZipCode>
            <rptOwnerStateDescription></rptOwnerStateDescription>
        </reportingOwnerAddress>
        <reportingOwnerRelationship>
            <isDirector>0</isDirector>
            <isOfficer>0</isOfficer>
            <isTenPercentOwner>1</isTenPercentOwner>
            <isOther>0</isOther>
            <officerTitle></officerTitle>
            <otherText></otherText>
        </reportingOwnerRelationship>
    </reportingOwner>

    <reportingOwner>
        <reportingOwnerId>
            <rptOwnerCik>0001102113</rptOwnerCik>
            <rptOwnerName>BANK OF AMERICA NA</rptOwnerName>
        </reportingOwnerId>
        <reportingOwnerAddress>
            <rptOwnerStreet1>101 S TRYON STREET</rptOwnerStreet1>
            <rptOwnerStreet2></rptOwnerStreet2>
            <rptOwnerCity>CHARLOTTE</rptOwnerCity>
            <rptOwnerState>NC</rptOwnerState>
            <rptOwnerZipCode>28255</rptOwnerZipCode>
            <rptOwnerStateDescription></rptOwnerStateDescription>
        </reportingOwnerAddress>
        <reportingOwnerRelationship>
            <isDirector>0</isDirector>
            <isOfficer>0</isOfficer>
            <isTenPercentOwner>1</isTenPercentOwner>
            <isOther>0</isOther>
            <officerTitle></officerTitle>
            <otherText></otherText>
        </reportingOwnerRelationship>
    </reportingOwner>

    <reportingOwner>
        <reportingOwnerId>
            <rptOwnerCik>0001453700</rptOwnerCik>
            <rptOwnerName>Blue Ridge Investments, L.L.C.</rptOwnerName>
        </reportingOwnerId>
        <reportingOwnerAddress>
            <rptOwnerStreet1>214 NORTH TRYON STREET</rptOwnerStreet1>
            <rptOwnerStreet2></rptOwnerStreet2>
            <rptOwnerCity>CHARLOTTE</rptOwnerCity>
            <rptOwnerState>NC</rptOwnerState>
            <rptOwnerZipCode>28255</rptOwnerZipCode>
            <rptOwnerStateDescription></rptOwnerStateDescription>
        </reportingOwnerAddress>
        <reportingOwnerRelationship>
            <isDirector>0</isDirector>
            <isOfficer>0</isOfficer>
            <isTenPercentOwner>1</isTenPercentOwner>
            <isOther>0</isOther>
            <officerTitle></officerTitle>
            <otherText></otherText>
        </reportingOwnerRelationship>
    </reportingOwner>

    <nonDerivativeTable>
        <nonDerivativeTransaction>
            <securityTitle>
                <value>Auction Rate Preferred</value>
                <footnoteId id="F1"/>
            </securityTitle>
            <transactionDate>
                <value>2012-01-18</value>
            </transactionDate>
            <deemedExecutionDate></deemedExecutionDate>
            <transactionCoding>
                <transactionFormType>4</transactionFormType>
                <transactionCode>J</transactionCode>
                <equitySwapInvolved>0</equitySwapInvolved>
                <footnoteId id="F2"/>
            </transactionCoding>
            <transactionAmounts>
                <transactionShares>
                    <value>1467</value>
                </transactionShares>
                <transactionPricePerShare>
                    <footnoteId id="F2"/>
                </transactionPricePerShare>
                <transactionAcquiredDisposedCode>
                    <value>D</value>
                </transactionAcquiredDisposedCode>
            </transactionAmounts>
            <postTransactionAmounts>
                <sharesOwnedFollowingTransaction>
                    <value>0</value>
                </sharesOwnedFollowingTransaction>
            </postTransactionAmounts>
            <ownershipNature>
                <directOrIndirectOwnership>
                    <value>I</value>
                </directOrIndirectOwnership>
                <natureOfOwnership>
                    <value>See Footnote</value>
                    <footnoteId id="F1"/>
                </natureOfOwnership>
            </ownershipNature>
        </nonDerivativeTransaction>
    </nonDerivativeTable>

    <derivativeTable></derivativeTable>

    <footnotes>
        <footnote id="F1">The Auction Rate Preferred Shares (&quot;Shares&quot;) reported in Table I represent shares beneficially owned by Bank of America N.A. (&quot;BANA&quot;) and Blue Ridge Investors, L.L.C. (&quot;Blue Ridge&quot;). BANA and Blue Ridge are wholly owned subsidiaries of Bank of America Corporation (&quot;Bank of America&quot;).</footnote>
        <footnote id="F2">The Shares were called for redemption by the issuer at par value.</footnote>
    </footnotes>

    <remarks></remarks>

    <ownerSignature>
        <signatureName>/s/ Michael Didovic</signatureName>
        <signatureDate>2012-01-20</signatureDate>
    </ownerSignature>

    <ownerSignature>
        <signatureName>/s/ Greg Todd</signatureName>
        <signatureDate>2012-01-20</signatureDate>
    </ownerSignature>
</ownershipDocument>
</XML>
</TEXT>
</DOCUMENT>
</SEC-DOCUMENT>
