<?xml version="1.0"?>
<ownershipDocument>

    <schemaVersion>X0202</schemaVersion>

    <documentType>4</documentType>

    <periodOfReport>2007-09-19</periodOfReport>

    <notSubjectToSection16>0</notSubjectToSection16>

    <issuer>
        <issuerCik>0000315189</issuerCik>
        <issuerName>DEERE &amp; CO</issuerName>
        <issuerTradingSymbol>DE</issuerTradingSymbol>
    </issuer>

    <reportingOwner>
        <reportingOwnerId>
            <rptOwnerCik>0001196260</rptOwnerCik>
            <rptOwnerName>JENKINS JAMES R</rptOwnerName>
        </reportingOwnerId>
        <reportingOwnerAddress>
            <rptOwnerStreet1>DEERE &amp; COMPANY</rptOwnerStreet1>
            <rptOwnerStreet2>ONE JOHN DEERE PLACE</rptOwnerStreet2>
            <rptOwnerCity>MOLINE</rptOwnerCity>
            <rptOwnerState>IL</rptOwnerState>
            <rptOwnerZipCode>61265</rptOwnerZipCode>
            <rptOwnerStateDescription></rptOwnerStateDescription>
        </reportingOwnerAddress>
        <reportingOwnerRelationship>
            <isDirector>0</isDirector>
            <isOfficer>1</isOfficer>
            <isTenPercentOwner>0</isTenPercentOwner>
            <isOther>0</isOther>
            <officerTitle>Senior V.P. &amp; General Counsel</officerTitle>
        </reportingOwnerRelationship>
    </reportingOwner>

    <nonDerivativeTable>
        <nonDerivativeTransaction>
            <securityTitle>
                <value>$1 Par Common Stock</value>
                <footnoteId id="F1"/>
                <footnoteId id="F2"/>
            </securityTitle>
            <transactionDate>
                <value>2007-09-19</value>
            </transactionDate>
            <transactionCoding>
                <transactionFormType>4</transactionFormType>
                <transactionCode>S</transactionCode>
                <equitySwapInvolved>0</equitySwapInvolved>
            </transactionCoding>
            <transactionTimeliness>
                <value></value>
            </transactionTimeliness>
            <transactionAmounts>
                <transactionShares>
                    <value>100</value>
                </transactionShares>
                <transactionPricePerShare>
                    <value>149.18</value>
                </transactionPricePerShare>
                <transactionAcquiredDisposedCode>
                    <value>D</value>
                </transactionAcquiredDisposedCode>
            </transactionAmounts>
            <postTransactionAmounts>
                <sharesOwnedFollowingTransaction>
                    <value>58932</value>
                    <footnoteId id="F3"/>
                </sharesOwnedFollowingTransaction>
            </postTransactionAmounts>
            <ownershipNature>
                <directOrIndirectOwnership>
                    <value>D</value>
                </directOrIndirectOwnership>
            </ownershipNature>
        </nonDerivativeTransaction>
    </nonDerivativeTable>

    <footnotes>
        <footnote id="F1">References to Deere &amp; Company stock include associated preferred stock rights.</footnote>
        <footnote id="F2">Sale of shares pursuant to a Rule 10 (b) 5-1 stock sale plan executed on December 7, 2006.</footnote>
        <footnote id="F3">Includes 52,943 restricted stock units subject to restrictions or limitations under the John Deere Omnibus Equity and Incentive Plan.  Shares are not held by reporting person during the period of limitation or restriction.  Units include the ability to have shares withheld to satisfy income tax obligations.</footnote>
    </footnotes>

    <ownerSignature>
        <signatureName>/s/ Paul Wilczynski, Assistant Secretary, Deere &amp; Company, Under Power of Attorney</signatureName>
        <signatureDate>2007-09-20</signatureDate>
    </ownerSignature>
</ownershipDocument>
