-----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,
 LVjuVnVuKK9OYfMykpYZmqHxTyEeifM1ojfrJ4XpNdsUPQdSxnlcxjmcBLQIoO3M
 +fSJ1hpNvSk7+RusI0kvhw==

<SEC-DOCUMENT>0000920371-03-000053.txt : 20030911
<SEC-HEADER>0000920371-03-000053.hdr.sgml : 20030911
<ACCEPTANCE-DATETIME>20030911132310
ACCESSION NUMBER:		0000920371-03-000053
CONFORMED SUBMISSION TYPE:	4
PUBLIC DOCUMENT COUNT:		1
CONFORMED PERIOD OF REPORT:	20030909
FILED AS OF DATE:		20030911

REPORTING-OWNER:	

	OWNER DATA:	
		COMPANY CONFORMED NAME:			TOWNSEND DONALD M
		CENTRAL INDEX KEY:			0001036046

	FILING VALUES:
		FORM TYPE:		4
		SEC ACT:		1934 Act
		SEC FILE NUMBER:	001-13429
		FILM NUMBER:		03891550

	BUSINESS ADDRESS:	
		STREET 1:		4120 DUBLIN BOULEVARD
		STREET 2:		SUITE 400
		CITY:			DUBLIN
		STATE:			CA
		ZIP:			94568

	MAIL ADDRESS:	
		STREET 1:		4120 DUBLIN BOULEVARD
		STREET 2:		SUITE 400
		CITY:			DUBLIN
		STATE:			CA
		ZIP:			94568

	FORMER NAME:	
		FORMER CONFORMED NAME:	TOWSEND DONALD M
		DATE OF NAME CHANGE:	19970319

ISSUER:		

	COMPANY DATA:	
		COMPANY CONFORMED NAME:			SIMPSON MANUFACTURING CO INC /CA/
		CENTRAL INDEX KEY:			0000920371
		STANDARD INDUSTRIAL CLASSIFICATION:	CUTLERY, HANDTOOLS & GENERAL HARDWARE [3420]
		IRS NUMBER:				943196943
		STATE OF INCORPORATION:			DE
		FISCAL YEAR END:			1231

	BUSINESS ADDRESS:	
		STREET 1:		4120 DUBLILN BLVD STE 400
		CITY:			DUBLIN
		STATE:			CA
		ZIP:			94568
		BUSINESS PHONE:		9255609000

	MAIL ADDRESS:	
		STREET 1:		4120 DUBLIN BLVD STE 400
		CITY:			DUBLIN
		STATE:			CA
		ZIP:			94568
</SEC-HEADER>
<DOCUMENT>
<TYPE>4
<SEQUENCE>1
<FILENAME>edgar.xml
<DESCRIPTION>PRIMARY DOCUMENT
<TEXT>
<XML>
<?xml version="1.0"?>
<ownershipDocument>
    <schemaVersion>X0201</schemaVersion>

    <documentType>4</documentType><periodOfReport>2003-09-09</periodOfReport>
    <issuer>
        <issuerCik>0000920371</issuerCik>
        <issuerName>SIMPSON MANUFACTURING CO INC /CA/</issuerName>
        <issuerTradingSymbol>NYSE:SSD</issuerTradingSymbol></issuer><reportingOwner>
        <reportingOwnerId>
            <rptOwnerCik>0001036046</rptOwnerCik>
            <rptOwnerName>TOWNSEND DONALD M</rptOwnerName>
        </reportingOwnerId>
        <reportingOwnerAddress>
            <rptOwnerStreet1>4120 DUBLIN BLVD., SUITE 400</rptOwnerStreet1>
            <rptOwnerStreet2></rptOwnerStreet2>
            <rptOwnerCity>DUBLIN</rptOwnerCity>
            <rptOwnerState>CA</rptOwnerState>
            <rptOwnerZipCode>94568</rptOwnerZipCode>
            <rptOwnerStateDescription></rptOwnerStateDescription>
        </reportingOwnerAddress>
            <reportingOwnerRelationship>
<isDirector>0</isDirector><isOfficer>1</isOfficer><isTenPercentOwner>0</isTenPercentOwner><isOther>0</isOther><officerTitle>Pres. &amp; CEO, Simpson Dura-Vent</officerTitle></reportingOwnerRelationship></reportingOwner><nonDerivativeTable><nonDerivativeTransaction><securityTitle><value>Common Stock</value></securityTitle><transactionDate><value>2003-09-09</value></transactionDate><transactionCoding><transactionFormType>4</transactionFormType><transactionCode>S</transactionCode><equitySwapInvolved>0</equitySwapInvolved></transactionCoding><transactionAmounts><transactionShares><value>15777</value></transactionShares><transactionPricePerShare><value>44.8514</value></transactionPricePerShare><transactionAcquiredDisposedCode><value>D</value></transactionAcquiredDisposedCode></transactionAmounts><postTransactionAmounts><sharesOwnedFollowingTransaction><value>15779</value></sharesOwnedFollowingTransaction></postTransactionAmounts><ownershipNature><directOrIndirectOwnership><value>D</value></directOrIndirectOwnersh
ip><natureOfOwnership><value/></natureOfOwnership></ownershipNature></nonDerivativeTransaction><nonDerivativeTransaction><securityTitle><value>Common Stock</value></securityTitle><transactionDate><value>2003-09-11</value></transactionDate><transactionCoding><transactionFormType>4</transactionFormType><transactionCode>X</transactionCode><equitySwapInvolved>0</equitySwapInvolved></transactionCoding><transactionAmounts><transactionShares><value>1250</value></transactionShares><transactionPricePerShare><value>21.875</value></transactionPricePerShare><transactionAcquiredDisposedCode><value>A</value></transactionAcquiredDisposedCode></transactionAmounts><postTransactionAmounts><sharesOwnedFollowingTransaction><value>17029</value></sharesOwnedFollowingTransaction></postTransactionAmounts><ownershipNature><directOrIndirectOwnership><value>D</value></directOrIndirectOwnership><natureOfOwnership><value/></natureOfOwnership></ownershipNature></nonDerivativeTransaction><nonDerivativeTransaction><securityTitle><value>Com
mon Stock</value></securityTitle><transactionDate><value>2003-09-11</value></transactionDate><transactionCoding><transactionFormType>4</transactionFormType><transactionCode>X</transactionCode><equitySwapInvolved>0</equitySwapInvolved></transactionCoding><transactionAmounts><transactionShares><value>1250</value></transactionShares><transactionPricePerShare><value>43.16</value></transactionPricePerShare><transactionAcquiredDisposedCode><value>D</value></transactionAcquiredDisposedCode></transactionAmounts><postTransactionAmounts><sharesOwnedFollowingTransaction><value>15779</value></sharesOwnedFollowingTransaction></postTransactionAmounts><ownershipNature><directOrIndirectOwnership><value>D</value></directOrIndirectOwnership><natureOfOwnership><value/></natureOfOwnership></ownershipNature></nonDerivativeTransaction></nonDerivativeTable><derivativeTable><derivativeTransaction><securityTitle><value>Options on Common Stock</value></securityTitle><conversionOrExercisePrice><value>21.875</value></conversionOrExerci
sePrice><transactionDate><value>2003-09-11</value></transactionDate><transactionCoding><transactionFormType>4</transactionFormType><transactionCode>X</transactionCode><equitySwapInvolved>0</equitySwapInvolved></transactionCoding><transactionAmounts><transactionShares><value>1250</value></transactionShares><transactionPricePerShare><value>21.875</value></transactionPricePerShare><transactionAcquiredDisposedCode><value>D</value></transactionAcquiredDisposedCode></transactionAmounts><exerciseDate><value>2001-01-01</value><footnoteId id="F1"/></exerciseDate><expirationDate><value>2006-12-31</value></expirationDate><underlyingSecurity><underlyingSecurityTitle><value>Common Stock</value></underlyingSecurityTitle><underlyingSecurityShares><value>1250</value></underlyingSecurityShares></underlyingSecurity><postTransactionAmounts><sharesOwnedFollowingTransaction><value>0</value></sharesOwnedFollowingTransaction></postTransactionAmounts><ownershipNature><directOrIndirectOwnership><value>D</value></directOrIndirectOwne
rship><natureOfOwnership><value/></natureOfOwnership></ownershipNature></derivativeTransaction><derivativeHolding><securityTitle><value>Options on Common Stock</value></securityTitle><conversionOrExercisePrice><value>21.875</value></conversionOrExercisePrice><exerciseDate><value>2001-01-01</value><footnoteId id="F1"/></exerciseDate><expirationDate><value>2006-12-31</value></expirationDate><underlyingSecurity><underlyingSecurityTitle><value>Common Stock</value></underlyingSecurityTitle><underlyingSecurityShares><value>1250</value></underlyingSecurityShares></underlyingSecurity><postTransactionAmounts><sharesOwnedFollowingTransaction><value>1250</value></sharesOwnedFollowingTransaction></postTransactionAmounts><ownershipNature><directOrIndirectOwnership><value>D</value></directOrIndirectOwnership><natureOfOwnership><value/></natureOfOwnership></ownershipNature></derivativeHolding></derivativeTable><footnotes><footnote id="F1">This date represents the date of the first annual vesting period. This option vests e
qually over four years beginning with the date of grant.</footnote></footnotes><remarks/><ownerSignature><signatureName>/s/DONALD M. TOWNSEND</signatureName><signatureDate>2003-09-11</signatureDate></ownerSignature></ownershipDocument>

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</SEC-DOCUMENT>
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