<SEC-DOCUMENT>0001209191-12-030491.txt : 20120525
<SEC-HEADER>0001209191-12-030491.hdr.sgml : 20120525
<ACCEPTANCE-DATETIME>20120525135442
ACCESSION NUMBER:		0001209191-12-030491
CONFORMED SUBMISSION TYPE:	4
PUBLIC DOCUMENT COUNT:		1
CONFORMED PERIOD OF REPORT:	20120523
FILED AS OF DATE:		20120525
DATE AS OF CHANGE:		20120525

REPORTING-OWNER:	

	OWNER DATA:	
		COMPANY CONFORMED NAME:			Shearer Bob
		CENTRAL INDEX KEY:			0001374803

	FILING VALUES:
		FORM TYPE:		4
		SEC ACT:		1934 Act
		SEC FILE NUMBER:	811-22606
		FILM NUMBER:		12870480

	MAIL ADDRESS:	
		STREET 1:		100 BELLEVUE PARKWAY
		CITY:			WILMINGTON
		STATE:			DE
		ZIP:			19809

ISSUER:		

	COMPANY DATA:	
		COMPANY CONFORMED NAME:			BlackRock Utility & Infrastructure Trust
		CENTRAL INDEX KEY:			0001528988
		IRS NUMBER:				000000000
		STATE OF INCORPORATION:			DE
		FISCAL YEAR END:			1031

	BUSINESS ADDRESS:	
		STREET 1:		55 EAST 52ND STREET
		CITY:			NEW YORK
		STATE:			NY
		ZIP:			10055
		BUSINESS PHONE:		(800) 882-0052

	MAIL ADDRESS:	
		STREET 1:		55 EAST 52ND STREET
		CITY:			NEW YORK
		STATE:			NY
		ZIP:			10055
</SEC-HEADER>
<DOCUMENT>
<TYPE>4
<SEQUENCE>1
<FILENAME>doc4.xml
<DESCRIPTION>FORM 4 SUBMISSION
<TEXT>
<XML>
<?xml version="1.0"?>
<ownershipDocument>

    <schemaVersion>X0305</schemaVersion>

    <documentType>4</documentType>

    <periodOfReport>2012-05-23</periodOfReport>

    <notSubjectToSection16>0</notSubjectToSection16>

    <issuer>
        <issuerCik>0001528988</issuerCik>
        <issuerName>BlackRock Utility &amp; Infrastructure Trust</issuerName>
        <issuerTradingSymbol>BUI</issuerTradingSymbol>
    </issuer>

    <reportingOwner>
        <reportingOwnerId>
            <rptOwnerCik>0001374803</rptOwnerCik>
            <rptOwnerName>Shearer Bob</rptOwnerName>
        </reportingOwnerId>
        <reportingOwnerAddress>
            <rptOwnerStreet1>55 EAST 52ND STREET</rptOwnerStreet1>
            <rptOwnerStreet2></rptOwnerStreet2>
            <rptOwnerCity>NEW YORK</rptOwnerCity>
            <rptOwnerState>NY</rptOwnerState>
            <rptOwnerZipCode>10055</rptOwnerZipCode>
            <rptOwnerStateDescription></rptOwnerStateDescription>
        </reportingOwnerAddress>
        <reportingOwnerRelationship>
            <isDirector>0</isDirector>
            <isOfficer>0</isOfficer>
            <isTenPercentOwner>0</isTenPercentOwner>
            <isOther>1</isOther>
            <otherText>Portfolio Manager</otherText>
        </reportingOwnerRelationship>
    </reportingOwner>

    <nonDerivativeTable>
        <nonDerivativeTransaction>
            <securityTitle>
                <value>Common Shares</value>
            </securityTitle>
            <transactionDate>
                <value>2012-05-23</value>
            </transactionDate>
            <deemedExecutionDate></deemedExecutionDate>
            <transactionCoding>
                <transactionFormType>4</transactionFormType>
                <transactionCode>P</transactionCode>
                <equitySwapInvolved>0</equitySwapInvolved>
            </transactionCoding>
            <transactionTimeliness>
                <value></value>
            </transactionTimeliness>
            <transactionAmounts>
                <transactionShares>
                    <value>5000</value>
                </transactionShares>
                <transactionPricePerShare>
                    <value>17.7303</value>
                    <footnoteId id="F1"/>
                </transactionPricePerShare>
                <transactionAcquiredDisposedCode>
                    <value>A</value>
                </transactionAcquiredDisposedCode>
            </transactionAmounts>
            <postTransactionAmounts>
                <sharesOwnedFollowingTransaction>
                    <value>5000</value>
                </sharesOwnedFollowingTransaction>
            </postTransactionAmounts>
            <ownershipNature>
                <directOrIndirectOwnership>
                    <value>D</value>
                </directOrIndirectOwnership>
            </ownershipNature>
        </nonDerivativeTransaction>
    </nonDerivativeTable>

    <footnotes>
        <footnote id="F1">These shares were purchased in multiple transactions. The range of prices for the transactions reported in this line was 17.62 to 17.78. The Reporting Person undertakes to provide upon request by the Commission staff, the issuer, or the security holder of the issuer, full information regarding the number of shares purchased or sold at each separate price.</footnote>
    </footnotes>

    <remarks></remarks>

    <ownerSignature>
        <signatureName>/s/ Janey Ahn as attorney-in-fact</signatureName>
        <signatureDate>2012-05-25</signatureDate>
    </ownerSignature>
</ownershipDocument>
</XML>
</TEXT>
</DOCUMENT>
</SEC-DOCUMENT>
