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Proc-Type: 2001,MIC-CLEAR
Originator-Name: webmaster@www.sec.gov
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MIC-Info: RSA-MD5,RSA,
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<SEC-DOCUMENT>0001140361-10-041243.txt : 20101014
<SEC-HEADER>0001140361-10-041243.hdr.sgml : 20101014
<ACCEPTANCE-DATETIME>20101014193600
ACCESSION NUMBER:		0001140361-10-041243
CONFORMED SUBMISSION TYPE:	4
PUBLIC DOCUMENT COUNT:		1
CONFORMED PERIOD OF REPORT:	20101012
FILED AS OF DATE:		20101014
DATE AS OF CHANGE:		20101014

REPORTING-OWNER:	

	OWNER DATA:	
		COMPANY CONFORMED NAME:			NOBLE WILLIAM B
		CENTRAL INDEX KEY:			0001253564

	FILING VALUES:
		FORM TYPE:		4
		SEC ACT:		1934 Act
		SEC FILE NUMBER:	000-06936
		FILM NUMBER:		101124573

	MAIL ADDRESS:	
		STREET 1:		BRICK CLOSE, KIIN FARM
		CITY:			MILTON KEYNES
		STATE:			X0
		ZIP:			MK1 13LJ

ISSUER:		

	COMPANY DATA:	
		COMPANY CONFORMED NAME:			WD 40 CO
		CENTRAL INDEX KEY:			0000105132
		STANDARD INDUSTRIAL CLASSIFICATION:	MISCELLANEOUS CHEMICAL PRODUCTS [2890]
		IRS NUMBER:				951797918
		STATE OF INCORPORATION:			DE
		FISCAL YEAR END:			0831

	BUSINESS ADDRESS:	
		STREET 1:		1061 CUDAHY PL
		CITY:			SAN DIEGO
		STATE:			CA
		ZIP:			92110
		BUSINESS PHONE:		6192751400

	MAIL ADDRESS:	
		STREET 1:		1061 CUDAHY PLACE
		CITY:			SAN DIEGO
		STATE:			CA
		ZIP:			92110
</SEC-HEADER>
<DOCUMENT>
<TYPE>4
<SEQUENCE>1
<FILENAME>doc1.xml
<DESCRIPTION>FORM 4
<TEXT>
<XML>
<?xml version="1.0"?>
<ownershipDocument>

    <schemaVersion>X0303</schemaVersion>

    <documentType>4</documentType>

    <periodOfReport>2010-10-12</periodOfReport>

    <notSubjectToSection16>0</notSubjectToSection16>

    <issuer>
        <issuerCik>0000105132</issuerCik>
        <issuerName>WD 40 CO</issuerName>
        <issuerTradingSymbol>WDFC</issuerTradingSymbol>
    </issuer>

    <reportingOwner>
        <reportingOwnerId>
            <rptOwnerCik>0001253564</rptOwnerCik>
            <rptOwnerName>NOBLE WILLIAM B</rptOwnerName>
        </reportingOwnerId>
        <reportingOwnerAddress>
            <rptOwnerStreet1>BRICK CLOSE</rptOwnerStreet1>
            <rptOwnerStreet2>KIIN FARM</rptOwnerStreet2>
            <rptOwnerCity>MILTON KEYNES</rptOwnerCity>
            <rptOwnerState>X0</rptOwnerState>
            <rptOwnerZipCode>MK1 13LJ</rptOwnerZipCode>
            <rptOwnerStateDescription>UNITED KINGDOM</rptOwnerStateDescription>
        </reportingOwnerAddress>
        <reportingOwnerRelationship>
            <isDirector>0</isDirector>
            <isOfficer>1</isOfficer>
            <isTenPercentOwner>0</isTenPercentOwner>
            <isOther>0</isOther>
            <officerTitle>Managing Director, Europe</officerTitle>
            <otherText></otherText>
        </reportingOwnerRelationship>
    </reportingOwner>

    <nonDerivativeTable>
        <nonDerivativeTransaction>
            <securityTitle>
                <value>Common Stock</value>
            </securityTitle>
            <transactionDate>
                <value>2010-10-12</value>
            </transactionDate>
            <deemedExecutionDate></deemedExecutionDate>
            <transactionCoding>
                <transactionFormType>4</transactionFormType>
                <transactionCode>A</transactionCode>
                <equitySwapInvolved>0</equitySwapInvolved>
            </transactionCoding>
            <transactionAmounts>
                <transactionShares>
                    <value>1600</value>
                    <footnoteId id="F1"/>
                </transactionShares>
                <transactionPricePerShare>
                    <footnoteId id="F1"/>
                </transactionPricePerShare>
                <transactionAcquiredDisposedCode>
                    <value>A</value>
                </transactionAcquiredDisposedCode>
            </transactionAmounts>
            <postTransactionAmounts>
                <sharesOwnedFollowingTransaction>
                    <value>16167</value>
                </sharesOwnedFollowingTransaction>
            </postTransactionAmounts>
            <ownershipNature>
                <directOrIndirectOwnership>
                    <value>D</value>
                </directOrIndirectOwnership>
            </ownershipNature>
        </nonDerivativeTransaction>
        <nonDerivativeTransaction>
            <securityTitle>
                <value>Common Stock</value>
            </securityTitle>
            <transactionDate>
                <value>2010-10-12</value>
            </transactionDate>
            <deemedExecutionDate></deemedExecutionDate>
            <transactionCoding>
                <transactionFormType>4</transactionFormType>
                <transactionCode>A</transactionCode>
                <equitySwapInvolved>0</equitySwapInvolved>
            </transactionCoding>
            <transactionAmounts>
                <transactionShares>
                    <value>2400</value>
                    <footnoteId id="F2"/>
                </transactionShares>
                <transactionPricePerShare>
                    <footnoteId id="F2"/>
                </transactionPricePerShare>
                <transactionAcquiredDisposedCode>
                    <value>A</value>
                </transactionAcquiredDisposedCode>
            </transactionAmounts>
            <postTransactionAmounts>
                <sharesOwnedFollowingTransaction>
                    <value>18567</value>
                    <footnoteId id="F3"/>
                </sharesOwnedFollowingTransaction>
            </postTransactionAmounts>
            <ownershipNature>
                <directOrIndirectOwnership>
                    <value>D</value>
                </directOrIndirectOwnership>
            </ownershipNature>
        </nonDerivativeTransaction>
    </nonDerivativeTable>

    <derivativeTable></derivativeTable>

    <footnotes>
        <footnote id="F1">1,600 Restricted Stock Units (Common Stock equivalents) were granted pursant to the WD-40 Company 2007 Stock Incentive Plan. The Restricted Stock Units (RSUs) will be settled solely with Issuer Common Stock upon an annual vesting schedule as provided for in the Award Agreement for the RSUs as follows: 544 shares not later than 11/15/2011, 528 shares not later than 11/15/2012, and 528 shares not later than 11/15/2013.</footnote>
        <footnote id="F2">2,400 Performance Share Units (Common Stock equivalents) were granted pursuant to the 2007 Stock Incentive Plan. The Performance Share Units (PSUs) will be settled solely with Issuer Common Stock upon performance vesting as provided for in the Award Agreement for the PsUs following a 2 year performance measurement period.</footnote>
        <footnote id="F3">Total includes 10,636  Restricted Stock Units and 4,800 Performance Share Units.</footnote>
    </footnotes>

    <remarks></remarks>

    <ownerSignature>
        <signatureName>Maria M. Mitchell, as attorney-in-fact for William B. Noble</signatureName>
        <signatureDate>2010-10-14</signatureDate>
    </ownerSignature>
</ownershipDocument>
</XML>
</TEXT>
</DOCUMENT>
</SEC-DOCUMENT>
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