-----BEGIN PRIVACY-ENHANCED MESSAGE-----
Proc-Type: 2001,MIC-CLEAR
Originator-Name: webmaster@www.sec.gov
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MIC-Info: RSA-MD5,RSA,
 Ju/eh166Sxds5Nnjib0fX+2vx71Edesu2DteJZpsE2rr22sC2EKBQQ3phGipOc57
 9N7EcNKOsVRyph1oTQT5pA==

<SEC-DOCUMENT>0000014930-03-000065.txt : 20031103
<SEC-HEADER>0000014930-03-000065.hdr.sgml : 20031103
<ACCEPTANCE-DATETIME>20031103161854
ACCESSION NUMBER:		0000014930-03-000065
CONFORMED SUBMISSION TYPE:	4
PUBLIC DOCUMENT COUNT:		1
CONFORMED PERIOD OF REPORT:	20031031
FILED AS OF DATE:		20031103

REPORTING-OWNER:	

	OWNER DATA:	
		COMPANY CONFORMED NAME:			HARF PETER
		CENTRAL INDEX KEY:			0001223301

	FILING VALUES:
		FORM TYPE:		4
		SEC ACT:		1934 Act
		SEC FILE NUMBER:	001-01043
		FILM NUMBER:		03973272

	MAIL ADDRESS:	
		STREET 1:		HARF PETER
		STREET 2:		C/O BRUNSWICK CORP
		CITY:			LAKE FOREST
		STATE:			IL
		ZIP:			60045

ISSUER:		

	COMPANY DATA:	
		COMPANY CONFORMED NAME:			BRUNSWICK CORP
		CENTRAL INDEX KEY:			0000014930
		STANDARD INDUSTRIAL CLASSIFICATION:	ENGINES & TURBINES [3510]
		IRS NUMBER:				360848180
		STATE OF INCORPORATION:			DE
		FISCAL YEAR END:			1231

	BUSINESS ADDRESS:	
		STREET 1:		ONE N FIELD CT
		STREET 2:		C/O KRISTIN COLEMAN
		CITY:			LAKE FOREST
		STATE:			IL
		ZIP:			60045-4811
		BUSINESS PHONE:		8477354700

	MAIL ADDRESS:	
		STREET 1:		ONE N FIELD CT
		CITY:			LAKE FOREST
		STATE:			IL
		ZIP:			60045-4811

	FORMER COMPANY:	
		FORMER CONFORMED NAME:	BRUNSWICK BALKE COLLENDER CO
		DATE OF NAME CHANGE:	19660919
</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>2003-10-31</periodOfReport>


    <notSubjectToSection16>0</notSubjectToSection16>

    <issuer>
        <issuerCik>0000014930</issuerCik>
        <issuerName>BRUNSWICK CORP</issuerName>
        <issuerTradingSymbol>BC</issuerTradingSymbol>
    </issuer>

    <reportingOwner>
        <reportingOwnerId>
            <rptOwnerCik>0001223301</rptOwnerCik>
            <rptOwnerName>HARF PETER</rptOwnerName>
        </reportingOwnerId>
        <reportingOwnerAddress>
            <rptOwnerStreet1>HARF PETER</rptOwnerStreet1>
            <rptOwnerStreet2>C/O BRUNSWICK CORP</rptOwnerStreet2>
            <rptOwnerCity>LAKE FOREST</rptOwnerCity>
            <rptOwnerState>IL</rptOwnerState>
            <rptOwnerZipCode>60045</rptOwnerZipCode>
            <rptOwnerStateDescription></rptOwnerStateDescription>
        </reportingOwnerAddress>
        <reportingOwnerRelationship>
            <isDirector>1</isDirector>
            <isOfficer>0</isOfficer>
            <isTenPercentOwner>0</isTenPercentOwner>
            <isOther>0</isOther>
        </reportingOwnerRelationship>
    </reportingOwner>

    <nonDerivativeTable>

        <nonDerivativeTransaction>
            <securityTitle>
                <value>Common Stock</value>
                <footnoteId id="F1"/>
            </securityTitle>
            <transactionDate>
                <value>2003-10-31</value>
            </transactionDate>
            <transactionCoding>
                <transactionFormType>4</transactionFormType>
                <transactionCode>A</transactionCode>
                <equitySwapInvolved>0</equitySwapInvolved>
            </transactionCoding>
            <transactionTimeliness>
                <value></value>
            </transactionTimeliness>
            <transactionAmounts>
                <transactionShares>
                    <value>505</value>
                </transactionShares>
                <transactionPricePerShare>
                    <value>29.67</value>
                </transactionPricePerShare>
                <transactionAcquiredDisposedCode>
                    <value>A</value>
                </transactionAcquiredDisposedCode>
            </transactionAmounts>
            <postTransactionAmounts>
                <sharesOwnedFollowingTransaction>
                    <value>22139</value>
                </sharesOwnedFollowingTransaction>
            </postTransactionAmounts>
            <ownershipNature>
                <directOrIndirectOwnership>
                    <value>D</value>
                </directOrIndirectOwnership>
            </ownershipNature>
        </nonDerivativeTransaction>

        <nonDerivativeTransaction>
            <securityTitle>
                <value>Common Stock</value>
            </securityTitle>
            <transactionDate>
                <value>2003-10-31</value>
            </transactionDate>
            <transactionCoding>
                <transactionFormType>4</transactionFormType>
                <transactionCode>A</transactionCode>
                <equitySwapInvolved>0</equitySwapInvolved>
            </transactionCoding>
            <transactionTimeliness>
                <value></value>
            </transactionTimeliness>
            <transactionAmounts>
                <transactionShares>
                    <value>421</value>
                </transactionShares>
                <transactionPricePerShare>
                    <value>29.67</value>
                </transactionPricePerShare>
                <transactionAcquiredDisposedCode>
                    <value>A</value>
                </transactionAcquiredDisposedCode>
            </transactionAmounts>
            <postTransactionAmounts>
                <sharesOwnedFollowingTransaction>
                    <value>22560</value>
                </sharesOwnedFollowingTransaction>
            </postTransactionAmounts>
            <ownershipNature>
                <directOrIndirectOwnership>
                    <value>D</value>
                </directOrIndirectOwnership>
            </ownershipNature>
        </nonDerivativeTransaction>

        <nonDerivativeHolding>
            <securityTitle>
                <value>Common Stock</value>
            </securityTitle>
            <postTransactionAmounts>
                <sharesOwnedFollowingTransaction>
                    <value>25000</value>
                </sharesOwnedFollowingTransaction>
            </postTransactionAmounts>
            <ownershipNature>
                <directOrIndirectOwnership>
                    <value>I</value>
                </directOrIndirectOwnership>
                <natureOfOwnership>
                    <value>By Trust</value>
                </natureOfOwnership>
            </ownershipNature>
        </nonDerivativeHolding>

    </nonDerivativeTable>

    <footnotes>
        <footnote id="F1">These are deferred stock units in the director's deferred account and automatically will be distributed in predetermined installments of shares of common stock on a 1-for-1 basis after the director ceases being a director of the Company.</footnote>
    </footnotes>


    <ownerSignature>
        <signatureName>By Power of Attorney /s/ Peter Harf</signatureName>
        <signatureDate>2003-11-03</signatureDate>
    </ownerSignature>

</ownershipDocument>

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