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Proc-Type: 2001,MIC-CLEAR
Originator-Name: webmaster@www.sec.gov
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MIC-Info: RSA-MD5,RSA,
 Sa0GHsgoXR3F6RpHNgYazfKUrQripj92EcE4gmdeu1XBdXbCdB0njuXQjbpaLHsT
 hLIT589iRMCaaPAE+PP2Ng==

<SEC-DOCUMENT>0001182186-03-000005.txt : 20030618
<SEC-HEADER>0001182186-03-000005.hdr.sgml : 20030618
<ACCEPTANCE-DATETIME>20030618122044
ACCESSION NUMBER:		0001182186-03-000005
CONFORMED SUBMISSION TYPE:	4
PUBLIC DOCUMENT COUNT:		1
CONFORMED PERIOD OF REPORT:	20030616
FILED AS OF DATE:		20030618

REPORTING-OWNER:	

	OWNER DATA:	
		COMPANY CONFORMED NAME:			HAWKINS W WHITLEY
		CENTRAL INDEX KEY:			0001182186

	FILING VALUES:
		FORM TYPE:		4
		SEC ACT:		1934 Act
		SEC FILE NUMBER:	001-08796
		FILM NUMBER:		03748363

	BUSINESS ADDRESS:	
		STREET 1:		1801 OLDS COURT
		CITY:			MARCO ISLAND
		STATE:			FL
		ZIP:			34145
		BUSINESS PHONE:		9416420546

	FORMER NAME:	
		FORMER CONFORMED NAME:	HAWKINS W WHITNEY
		DATE OF NAME CHANGE:	20020822

ISSUER:		

	COMPANY DATA:	
		COMPANY CONFORMED NAME:			QUESTAR CORP
		CENTRAL INDEX KEY:			0000751652
		STANDARD INDUSTRIAL CLASSIFICATION:	NATURAL GAS TRANSMISSION & DISTRIBUTION [4923]
		IRS NUMBER:				870407509
		STATE OF INCORPORATION:			UT
		FISCAL YEAR END:			1231

	BUSINESS ADDRESS:	
		STREET 1:		180 EAST 100 SOUTH ST
		STREET 2:		PO BOX 45433
		CITY:			SALT LAKE CITY
		STATE:			UT
		ZIP:			84145
		BUSINESS PHONE:		8015345000

	MAIL ADDRESS:	
		STREET 1:		180 EAST 100 SOUTH ST
		STREET 2:		P O BOX 45433
		CITY:			SALT LAKE CITY
		STATE:			UT
		ZIP:			84145
</SEC-HEADER>
<DOCUMENT>
<TYPE>4
<SEQUENCE>1
<FILENAME>primary_doc.xml
<DESCRIPTION>PRIMARY DOCUMENT
<TEXT>
<XML>
<?xml version="1.0"?>

<ownershipDocument>

    <documentType>4</documentType>

    <periodOfReport>2003-06-16</periodOfReport>


    <notSubjectToSection16>0</notSubjectToSection16>

    <issuer>
        <issuerCik>0000751652</issuerCik>
        <issuerName>QUESTAR CORP</issuerName>
        <issuerTradingSymbol>STR</issuerTradingSymbol>
    </issuer>

    <reportingOwner>
        <reportingOwnerId>
            <rptOwnerCik>0001182186</rptOwnerCik>
            <rptOwnerName>HAWKINS W WHITLEY</rptOwnerName>
        </reportingOwnerId>
        <reportingOwnerAddress>
            <rptOwnerStreet1>  </rptOwnerStreet1>
            <rptOwnerStreet2>  </rptOwnerStreet2>
            <rptOwnerCity>  </rptOwnerCity>
            <rptOwnerState>  </rptOwnerState>
            <rptOwnerZipCode>  </rptOwnerZipCode>
        </reportingOwnerAddress>
        <reportingOwnerRelationship>
            <isDirector>1</isDirector>
            <isOfficer>0</isOfficer>
            <isTenPercentOwner>0</isTenPercentOwner>
            <isOther>0</isOther>
        </reportingOwnerRelationship>
    </reportingOwner>

    <derivativeSecurity>
        <securityTitle>
            <value>Phantom Stock Units</value>
        </securityTitle>
        <conversionOrExercisePrice>
            <value>34</value>
        </conversionOrExercisePrice>
        <transactionDate>
            <value>2003-06-16</value>
        </transactionDate>
        <transactionCoding>
            <transactionFormType>4</transactionFormType>
            <transactionCode>A</transactionCode>
            <equitySwapInvolved>0</equitySwapInvolved>
        </transactionCoding>
        <transactionTimeliness>
            <value></value>
        </transactionTimeliness>
        <transactionAmounts>
            <transactionShares>
                <value>20.3483</value>
            </transactionShares>
            <transactionValue>
                <value>34</value>
            </transactionValue>
            <transactionAcquiredDisposedCode>
                <value>A</value>
            </transactionAcquiredDisposedCode>
        </transactionAmounts>
        <exerciseDate>
            <value>1988-08-08</value>
        </exerciseDate>
        <expirationDate>
            <value>1988-08-08</value>
        </expirationDate>
        <underlyingSecurity>
            <underlyingSecurityTitle>
                <value>Phantom Stock Units</value>
            </underlyingSecurityTitle>
            <underlyingSecurityShares>
                <value>20.3483</value>
            </underlyingSecurityShares>
        </underlyingSecurity>
        <postTransactionAmounts>
            <sharesOwnedFollowingTransaction>
                <value>3760.0285</value>
                <footnoteId id="F1"/>
            </sharesOwnedFollowingTransaction>
        </postTransactionAmounts>
        <ownershipNature>
            <directOrIndirectOwnership>
                <value>D</value>
            </directOrIndirectOwnership>
        </ownershipNature>
    </derivativeSecurity>

    <footnotes>
        <footnote id="F1">I have an account balance of phantom stock units under a deferred compensation plan.  These units are credited with reinvested dividends.  These shares will be converted to cash upon my retirement.  This total does not include 16,565 shares of Common Stock or 50,000 shares covered by vested options.</footnote>
    </footnotes>

    <ownerSignature>
        <signatureName>Connie C. Holbrook, Attorney in Fact for W.W. Hawkins</signatureName>
        <signatureDate>2003-06-18</signatureDate>
    </ownerSignature>

</ownershipDocument>

</XML>
</TEXT>
</DOCUMENT>
</SEC-DOCUMENT>
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