<?xml version="1.0"?>

<ownershipDocument>

    <schemaVersion>X0201</schemaVersion>

    <documentType>4</documentType>

    <periodOfReport>2003-12-10</periodOfReport>


    <notSubjectToSection16>0</notSubjectToSection16>

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

    <reportingOwner>
        <reportingOwnerId>
            <rptOwnerCik>0001196902</rptOwnerCik>
            <rptOwnerName>MARKLEY H J</rptOwnerName>
        </reportingOwnerId>
        <reportingOwnerAddress>
            <rptOwnerStreet1>DEERE &amp; CO</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>Pres., Ag Div. NA,Aust,Asia</officerTitle>
        </reportingOwnerRelationship>
    </reportingOwner>

    <nonDerivativeTable>

        <nonDerivativeTransaction>
            <securityTitle>
                <value>$1 Par Common Stock</value>
                <footnoteId id="F1"/>
            </securityTitle>
            <transactionDate>
                <value>2003-12-10</value>
            </transactionDate>
            <transactionCoding>
                <transactionFormType>4</transactionFormType>
                <transactionCode>A</transactionCode>
                <equitySwapInvolved>0</equitySwapInvolved>
            </transactionCoding>
            <transactionTimeliness>
                <value></value>
            </transactionTimeliness>
            <transactionAmounts>
                <transactionShares>
                    <value>13200</value>
                    <footnoteId id="F2"/>
                </transactionShares>
                <transactionPricePerShare>
                    <value>0</value>
                </transactionPricePerShare>
                <transactionAcquiredDisposedCode>
                    <value>A</value>
                </transactionAcquiredDisposedCode>
            </transactionAmounts>
            <postTransactionAmounts>
                <sharesOwnedFollowingTransaction>
                    <value>40920</value>
                    <footnoteId id="F3"/>
                </sharesOwnedFollowingTransaction>
            </postTransactionAmounts>
            <ownershipNature>
                <directOrIndirectOwnership>
                    <value>D</value>
                    <footnoteId id="F4"/>
                </directOrIndirectOwnership>
            </ownershipNature>
        </nonDerivativeTransaction>

    </nonDerivativeTable>

    <derivativeTable>

        <derivativeTransaction>
            <securityTitle>
                <value>Market Priced Options</value>
                <footnoteId id="F5"/>
            </securityTitle>
            <conversionOrExercisePrice>
                <value>61.64</value>
            </conversionOrExercisePrice>
            <transactionDate>
                <value>2003-12-10</value>
            </transactionDate>
            <transactionCoding>
                <transactionFormType>4</transactionFormType>
                <transactionCode>A</transactionCode>
                <equitySwapInvolved>0</equitySwapInvolved>
            </transactionCoding>
            <transactionTimeliness>
                <value></value>
            </transactionTimeliness>
            <transactionAmounts>
                <transactionShares>
                    <value>33000</value>
                </transactionShares>
                <transactionPricePerShare>
                    <value>0</value>
                </transactionPricePerShare>
                <transactionAcquiredDisposedCode>
                    <value>A</value>
                </transactionAcquiredDisposedCode>
            </transactionAmounts>
            <exerciseDate>
                <value>2004-12-10</value>
                <footnoteId id="F6"/>
            </exerciseDate>
            <expirationDate>
                <value>2013-12-10</value>
            </expirationDate>
            <underlyingSecurity>
                <underlyingSecurityTitle>
                    <value>Common Stock</value>
                </underlyingSecurityTitle>
                <underlyingSecurityShares>
                    <value>33000</value>
                </underlyingSecurityShares>
            </underlyingSecurity>
            <postTransactionAmounts>
                <sharesOwnedFollowingTransaction>
                    <value>33000</value>
                </sharesOwnedFollowingTransaction>
            </postTransactionAmounts>
            <ownershipNature>
                <directOrIndirectOwnership>
                    <value>D</value>
                </directOrIndirectOwnership>
            </ownershipNature>
        </derivativeTransaction>

    </derivativeTable>

    <footnotes>
        <footnote id="F1">Includes associated preferred stock rights.</footnote>
        <footnote id="F2">Grant of restricted stock units under the John Deere Omnibus Equity and Incentive Plan.</footnote>
        <footnote id="F3">Includes 22,962 restricted stock units granted under the John Deere Omnibus Equity and Incentive Plan.</footnote>
        <footnote id="F4">The spouse of the reporting person also beneficially owns 5,130 shares of $1 par common stock of Deere &amp; Company. The filing of this statement shall not be construed as an admission that the undersigned is, for the purpose of Section 16 of the Securities Exchange Act of 1934, or for any other purpose, the beneficial owner of these shares.</footnote>
        <footnote id="F5">All options include the ability to withhold shares upon the exercise of the option to satisfy income tax obligations.</footnote>
        <footnote id="F6">The options become exercisable in three installments on December 10, 2004, December 12, 2005, and December 11, 2006.</footnote>
    </footnotes>


    <ownerSignature>
        <signatureName>/s/ James H. Becht, Secretary, Deere &amp; Company, Under Power of Attorney</signatureName>
        <signatureDate>2003-12-12</signatureDate>
    </ownerSignature>

</ownershipDocument>

