-----BEGIN PRIVACY-ENHANCED MESSAGE-----
Proc-Type: 2001,MIC-CLEAR
Originator-Name: webmaster@www.sec.gov
Originator-Key-Asymmetric:
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 TWSM7vrzLADbmYQaionwg5sDW3P6oaM5D3tdezXMm7z1T+B+twIDAQAB
MIC-Info: RSA-MD5,RSA,
 URY6l3t3oiDhevFoVsCtVK8RKTMsfjNeR5OwPEzDn7nos7++0f4u0sfTLT7bDCWM
 bCXE+vMSXBLeS8+DMIvsnQ==

<SEC-DOCUMENT>0001238745-03-000001.txt : 20031015
<SEC-HEADER>0001238745-03-000001.hdr.sgml : 20031014
<ACCEPTANCE-DATETIME>20031015175042
ACCESSION NUMBER:		0001238745-03-000001
CONFORMED SUBMISSION TYPE:	4
PUBLIC DOCUMENT COUNT:		1
CONFORMED PERIOD OF REPORT:	20031013
FILED AS OF DATE:		20031015

REPORTING-OWNER:	

	OWNER DATA:	
		COMPANY CONFORMED NAME:			LUDLOW WARREN J
		CENTRAL INDEX KEY:			0001238745

	FILING VALUES:
		FORM TYPE:		4
		SEC ACT:		1934 Act
		SEC FILE NUMBER:	000-22433
		FILM NUMBER:		03942514

	MAIL ADDRESS:	
		STREET 1:		6300 BRIDGE POINT PARKWAY
		STREET 2:		BLDG 2 SUITE 500
		CITY:			AUSTIN
		STATE:			TX
		ZIP:			78730

ISSUER:		

	COMPANY DATA:	
		COMPANY CONFORMED NAME:			BRIGHAM EXPLORATION CO
		CENTRAL INDEX KEY:			0001034755
		STANDARD INDUSTRIAL CLASSIFICATION:	CRUDE PETROLEUM & NATURAL GAS [1311]
		IRS NUMBER:				752692967
		STATE OF INCORPORATION:			DE
		FISCAL YEAR END:			1231

	BUSINESS ADDRESS:	
		STREET 1:		6300 BRIDGE POINT PARKWAY
		STREET 2:		BLDG 2 SUITE 500
		CITY:			AUSTIN
		STATE:			TX
		ZIP:			78730
		BUSINESS PHONE:		5124273300

	MAIL ADDRESS:	
		STREET 1:		6300 BRIDGE POINT PARKWAY
		STREET 2:		BLDG 2 SUITE 500
		CITY:			AUSTIN
		STATE:			TX
		ZIP:			78730
</SEC-HEADER>
<DOCUMENT>
<TYPE>4
<SEQUENCE>1
<FILENAME>primary_doc.xml
<DESCRIPTION>PRIMARY DOCUMENT
<TEXT>
<XML>
<?xml version="1.0"?>

<ownershipDocument>

    <schemaVersion>X0201</schemaVersion>

    <documentType>4</documentType>

    <periodOfReport>2003-10-13</periodOfReport>


    <notSubjectToSection16>0</notSubjectToSection16>

    <issuer>
        <issuerCik>0001034755</issuerCik>
        <issuerName>BRIGHAM EXPLORATION CO</issuerName>
        <issuerTradingSymbol>BEXP</issuerTradingSymbol>
    </issuer>

    <reportingOwner>
        <reportingOwnerId>
            <rptOwnerCik>0001238745</rptOwnerCik>
            <rptOwnerName>LUDLOW WARREN J</rptOwnerName>
        </reportingOwnerId>
        <reportingOwnerAddress>
            <rptOwnerStreet1>207 CRESCENT BLUFF</rptOwnerStreet1>
            <rptOwnerStreet2></rptOwnerStreet2>
            <rptOwnerCity>LAKEWAY</rptOwnerCity>
            <rptOwnerState>TX</rptOwnerState>
            <rptOwnerZipCode>78734</rptOwnerZipCode>
            <rptOwnerStateDescription></rptOwnerStateDescription>
        </reportingOwnerAddress>
        <reportingOwnerRelationship>
            <isDirector>0</isDirector>
            <isOfficer>1</isOfficer>
            <isTenPercentOwner>0</isTenPercentOwner>
            <isOther>0</isOther>
            <officerTitle>General Counsel and Corp. Sec.</officerTitle>
        </reportingOwnerRelationship>
    </reportingOwner>

    <derivativeTable>

        <derivativeTransaction>
            <securityTitle>
                <value>Stock Option pursuant to 1997 Incentive Plan</value>
            </securityTitle>
            <conversionOrExercisePrice>
                <value>6.725</value>
            </conversionOrExercisePrice>
            <transactionDate>
                <value>2003-10-13</value>
            </transactionDate>
            <transactionCoding>
                <transactionFormType>4</transactionFormType>
                <transactionCode>A</transactionCode>
                <equitySwapInvolved>0</equitySwapInvolved>
            </transactionCoding>
            <transactionTimeliness>
                <value></value>
            </transactionTimeliness>
            <transactionAmounts>
                <transactionShares>
                    <value>25000</value>
                </transactionShares>
                <transactionPricePerShare>
                    <footnoteId id="F2"/>
                </transactionPricePerShare>
                <transactionAcquiredDisposedCode>
                    <value>A</value>
                </transactionAcquiredDisposedCode>
            </transactionAmounts>
            <exerciseDate>
                <value>2004-10-13</value>
                <footnoteId id="F1"/>
            </exerciseDate>
            <expirationDate>
                <value>2010-10-13</value>
            </expirationDate>
            <underlyingSecurity>
                <underlyingSecurityTitle>
                    <value>Common Stock, par value $.01</value>
                </underlyingSecurityTitle>
                <underlyingSecurityShares>
                    <value>25000</value>
                </underlyingSecurityShares>
            </underlyingSecurity>
            <postTransactionAmounts>
                <sharesOwnedFollowingTransaction>
                    <value>45000</value>
                </sharesOwnedFollowingTransaction>
            </postTransactionAmounts>
            <ownershipNature>
                <directOrIndirectOwnership>
                    <value>D</value>
                </directOrIndirectOwnership>
            </ownershipNature>
        </derivativeTransaction>

    </derivativeTable>

    <footnotes>
        <footnote id="F1">The options vest in five equal annual installments beginning one year from the date of the grant.</footnote>
        <footnote id="F2">Employee incentive option granted pursuant to 1997 Incentive Plan, no additional consideration due other than payment of exercise price.</footnote>
    </footnotes>


    <ownerSignature>
        <signatureName>Warren J. Ludlow</signatureName>
        <signatureDate>2003-10-15</signatureDate>
    </ownerSignature>

</ownershipDocument>

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