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

    <schemaVersion>X0203</schemaVersion>

    <documentType>3</documentType>

    <periodOfReport>2008-06-24</periodOfReport>

    <noSecuritiesOwned>0</noSecuritiesOwned>

    <issuer>
        <issuerCik>0000866873</issuerCik>
        <issuerName>DEL MONTE FOODS CO</issuerName>
        <issuerTradingSymbol>DLM</issuerTradingSymbol>
    </issuer>

    <reportingOwner>
        <reportingOwnerId>
            <rptOwnerCik>0001438674</rptOwnerCik>
            <rptOwnerName>MUTO RICHARD W</rptOwnerName>
        </reportingOwnerId>
        <reportingOwnerAddress>
            <rptOwnerStreet1>PO BOX 193575</rptOwnerStreet1>
            <rptOwnerStreet2></rptOwnerStreet2>
            <rptOwnerCity>SAN FRANCISCO</rptOwnerCity>
            <rptOwnerState>CA</rptOwnerState>
            <rptOwnerZipCode>94119</rptOwnerZipCode>
            <rptOwnerStateDescription></rptOwnerStateDescription>
        </reportingOwnerAddress>
        <reportingOwnerRelationship>
            <isDirector>0</isDirector>
            <isOfficer>1</isOfficer>
            <isTenPercentOwner>0</isTenPercentOwner>
            <isOther>0</isOther>
            <officerTitle>SVP and Chief HR Officer</officerTitle>
        </reportingOwnerRelationship>
    </reportingOwner>

    <nonDerivativeTable>
        <nonDerivativeHolding>
            <securityTitle>
                <value>Common Stock, $0.01, par value</value>
            </securityTitle>
            <postTransactionAmounts>
                <sharesOwnedFollowingTransaction>
                    <value>23967</value>
                    <footnoteId id="F1"/>
                </sharesOwnedFollowingTransaction>
            </postTransactionAmounts>
            <ownershipNature>
                <directOrIndirectOwnership>
                    <value>D</value>
                </directOrIndirectOwnership>
                <natureOfOwnership>
                    <value></value>
                </natureOfOwnership>
            </ownershipNature>
        </nonDerivativeHolding>
    </nonDerivativeTable>

    <derivativeTable>
        <derivativeHolding>
            <securityTitle>
                <value>Performance Shares</value>
            </securityTitle>
            <conversionOrExercisePrice>
                <value>0</value>
            </conversionOrExercisePrice>
            <exerciseDate>
                <footnoteId id="F2"/>
            </exerciseDate>
            <expirationDate>
                <footnoteId id="F3"/>
            </expirationDate>
            <underlyingSecurity>
                <underlyingSecurityTitle>
                    <value>Common Stock</value>
                </underlyingSecurityTitle>
                <underlyingSecurityShares>
                    <value>2475</value>
                </underlyingSecurityShares>
            </underlyingSecurity>
            <ownershipNature>
                <directOrIndirectOwnership>
                    <value>D</value>
                </directOrIndirectOwnership>
                <natureOfOwnership>
                    <value></value>
                </natureOfOwnership>
            </ownershipNature>
        </derivativeHolding>
        <derivativeHolding>
            <securityTitle>
                <value>Performance Shares</value>
            </securityTitle>
            <conversionOrExercisePrice>
                <value>0</value>
            </conversionOrExercisePrice>
            <exerciseDate>
                <footnoteId id="F4"/>
            </exerciseDate>
            <expirationDate>
                <footnoteId id="F3"/>
            </expirationDate>
            <underlyingSecurity>
                <underlyingSecurityTitle>
                    <value>Common Stock</value>
                </underlyingSecurityTitle>
                <underlyingSecurityShares>
                    <value>3800</value>
                </underlyingSecurityShares>
            </underlyingSecurity>
            <ownershipNature>
                <directOrIndirectOwnership>
                    <value>D</value>
                </directOrIndirectOwnership>
                <natureOfOwnership>
                    <value></value>
                </natureOfOwnership>
            </ownershipNature>
        </derivativeHolding>
        <derivativeHolding>
            <securityTitle>
                <value>Performance Shares</value>
            </securityTitle>
            <conversionOrExercisePrice>
                <value>0</value>
            </conversionOrExercisePrice>
            <exerciseDate>
                <footnoteId id="F5"/>
            </exerciseDate>
            <expirationDate>
                <footnoteId id="F3"/>
            </expirationDate>
            <underlyingSecurity>
                <underlyingSecurityTitle>
                    <value>Common Stock</value>
                </underlyingSecurityTitle>
                <underlyingSecurityShares>
                    <value>4500</value>
                </underlyingSecurityShares>
            </underlyingSecurity>
            <ownershipNature>
                <directOrIndirectOwnership>
                    <value>D</value>
                </directOrIndirectOwnership>
                <natureOfOwnership>
                    <value></value>
                </natureOfOwnership>
            </ownershipNature>
        </derivativeHolding>
        <derivativeHolding>
            <securityTitle>
                <value>Performance Shares</value>
            </securityTitle>
            <conversionOrExercisePrice>
                <value>0</value>
            </conversionOrExercisePrice>
            <exerciseDate>
                <footnoteId id="F6"/>
            </exerciseDate>
            <expirationDate>
                <footnoteId id="F7"/>
            </expirationDate>
            <underlyingSecurity>
                <underlyingSecurityTitle>
                    <value>Common Stock</value>
                </underlyingSecurityTitle>
                <underlyingSecurityShares>
                    <value>7650</value>
                </underlyingSecurityShares>
            </underlyingSecurity>
            <ownershipNature>
                <directOrIndirectOwnership>
                    <value>D</value>
                </directOrIndirectOwnership>
                <natureOfOwnership>
                    <value></value>
                </natureOfOwnership>
            </ownershipNature>
        </derivativeHolding>
        <derivativeHolding>
            <securityTitle>
                <value>Stock Option (right to purchase)</value>
            </securityTitle>
            <conversionOrExercisePrice>
                <value>13.00</value>
            </conversionOrExercisePrice>
            <exerciseDate>
                <footnoteId id="F8"/>
            </exerciseDate>
            <expirationDate>
                <value>2008-12-05</value>
            </expirationDate>
            <underlyingSecurity>
                <underlyingSecurityTitle>
                    <value>Common Stoc,, $0.01, par value</value>
                </underlyingSecurityTitle>
                <underlyingSecurityShares>
                    <value>22500</value>
                </underlyingSecurityShares>
            </underlyingSecurity>
            <ownershipNature>
                <directOrIndirectOwnership>
                    <value>D</value>
                </directOrIndirectOwnership>
                <natureOfOwnership>
                    <value></value>
                </natureOfOwnership>
            </ownershipNature>
        </derivativeHolding>
        <derivativeHolding>
            <securityTitle>
                <value>Stock Option (right to purchase)</value>
            </securityTitle>
            <conversionOrExercisePrice>
                <value>6.91</value>
            </conversionOrExercisePrice>
            <exerciseDate>
                <footnoteId id="F8"/>
            </exerciseDate>
            <expirationDate>
                <value>2010-08-10</value>
            </expirationDate>
            <underlyingSecurity>
                <underlyingSecurityTitle>
                    <value>Common Stoc,, $0.01, par value</value>
                </underlyingSecurityTitle>
                <underlyingSecurityShares>
                    <value>11250</value>
                </underlyingSecurityShares>
            </underlyingSecurity>
            <ownershipNature>
                <directOrIndirectOwnership>
                    <value>D</value>
                </directOrIndirectOwnership>
                <natureOfOwnership>
                    <value></value>
                </natureOfOwnership>
            </ownershipNature>
        </derivativeHolding>
        <derivativeHolding>
            <securityTitle>
                <value>Stock Option (right to purchase)</value>
            </securityTitle>
            <conversionOrExercisePrice>
                <value>8.87</value>
            </conversionOrExercisePrice>
            <exerciseDate>
                <footnoteId id="F8"/>
            </exerciseDate>
            <expirationDate>
                <value>2011-08-28</value>
            </expirationDate>
            <underlyingSecurity>
                <underlyingSecurityTitle>
                    <value>Common Stoc,, $0.01, par value</value>
                </underlyingSecurityTitle>
                <underlyingSecurityShares>
                    <value>17050</value>
                </underlyingSecurityShares>
            </underlyingSecurity>
            <ownershipNature>
                <directOrIndirectOwnership>
                    <value>D</value>
                </directOrIndirectOwnership>
                <natureOfOwnership>
                    <value></value>
                </natureOfOwnership>
            </ownershipNature>
        </derivativeHolding>
        <derivativeHolding>
            <securityTitle>
                <value>Stock Option (right to purchase)</value>
            </securityTitle>
            <conversionOrExercisePrice>
                <value>7.56</value>
            </conversionOrExercisePrice>
            <exerciseDate>
                <footnoteId id="F8"/>
            </exerciseDate>
            <expirationDate>
                <value>2012-10-07</value>
            </expirationDate>
            <underlyingSecurity>
                <underlyingSecurityTitle>
                    <value>Common Stoc,, $0.01, par value</value>
                </underlyingSecurityTitle>
                <underlyingSecurityShares>
                    <value>17050</value>
                </underlyingSecurityShares>
            </underlyingSecurity>
            <ownershipNature>
                <directOrIndirectOwnership>
                    <value>D</value>
                </directOrIndirectOwnership>
                <natureOfOwnership>
                    <value></value>
                </natureOfOwnership>
            </ownershipNature>
        </derivativeHolding>
        <derivativeHolding>
            <securityTitle>
                <value>Stock Option (right to purchase)</value>
            </securityTitle>
            <conversionOrExercisePrice>
                <value>7.37</value>
            </conversionOrExercisePrice>
            <exerciseDate>
                <footnoteId id="F8"/>
            </exerciseDate>
            <expirationDate>
                <value>2013-04-08</value>
            </expirationDate>
            <underlyingSecurity>
                <underlyingSecurityTitle>
                    <value>Common Stoc,, $0.01, par value</value>
                </underlyingSecurityTitle>
                <underlyingSecurityShares>
                    <value>25000</value>
                </underlyingSecurityShares>
            </underlyingSecurity>
            <ownershipNature>
                <directOrIndirectOwnership>
                    <value>D</value>
                </directOrIndirectOwnership>
                <natureOfOwnership>
                    <value></value>
                </natureOfOwnership>
            </ownershipNature>
        </derivativeHolding>
        <derivativeHolding>
            <securityTitle>
                <value>Stock Option (right to purchase)</value>
            </securityTitle>
            <conversionOrExercisePrice>
                <value>8.78</value>
            </conversionOrExercisePrice>
            <exerciseDate>
                <footnoteId id="F8"/>
            </exerciseDate>
            <expirationDate>
                <value>2013-09-12</value>
            </expirationDate>
            <underlyingSecurity>
                <underlyingSecurityTitle>
                    <value>Common Stoc,, $0.01, par value</value>
                </underlyingSecurityTitle>
                <underlyingSecurityShares>
                    <value>33200</value>
                </underlyingSecurityShares>
            </underlyingSecurity>
            <ownershipNature>
                <directOrIndirectOwnership>
                    <value>D</value>
                </directOrIndirectOwnership>
                <natureOfOwnership>
                    <value></value>
                </natureOfOwnership>
            </ownershipNature>
        </derivativeHolding>
        <derivativeHolding>
            <securityTitle>
                <value>Stock Option (right to purchase)</value>
            </securityTitle>
            <conversionOrExercisePrice>
                <value>10.59</value>
            </conversionOrExercisePrice>
            <exerciseDate>
                <footnoteId id="F9"/>
            </exerciseDate>
            <expirationDate>
                <value>2014-09-22</value>
            </expirationDate>
            <underlyingSecurity>
                <underlyingSecurityTitle>
                    <value>Common Stoc,, $0.01, par value</value>
                </underlyingSecurityTitle>
                <underlyingSecurityShares>
                    <value>25000</value>
                </underlyingSecurityShares>
            </underlyingSecurity>
            <ownershipNature>
                <directOrIndirectOwnership>
                    <value>D</value>
                </directOrIndirectOwnership>
                <natureOfOwnership>
                    <value></value>
                </natureOfOwnership>
            </ownershipNature>
        </derivativeHolding>
        <derivativeHolding>
            <securityTitle>
                <value>Stock Option (right to purchase)</value>
            </securityTitle>
            <conversionOrExercisePrice>
                <value>10.24</value>
            </conversionOrExercisePrice>
            <exerciseDate>
                <footnoteId id="F9"/>
            </exerciseDate>
            <expirationDate>
                <value>2015-09-29</value>
            </expirationDate>
            <underlyingSecurity>
                <underlyingSecurityTitle>
                    <value>Common Stoc,, $0.01, par value</value>
                </underlyingSecurityTitle>
                <underlyingSecurityShares>
                    <value>16000</value>
                </underlyingSecurityShares>
            </underlyingSecurity>
            <ownershipNature>
                <directOrIndirectOwnership>
                    <value>D</value>
                </directOrIndirectOwnership>
                <natureOfOwnership>
                    <value></value>
                </natureOfOwnership>
            </ownershipNature>
        </derivativeHolding>
        <derivativeHolding>
            <securityTitle>
                <value>Stock Option (right to purchase)</value>
            </securityTitle>
            <conversionOrExercisePrice>
                <value>10.37</value>
            </conversionOrExercisePrice>
            <exerciseDate>
                <footnoteId id="F9"/>
            </exerciseDate>
            <expirationDate>
                <value>2016-09-21</value>
            </expirationDate>
            <underlyingSecurity>
                <underlyingSecurityTitle>
                    <value>Common Stoc,, $0.01, par value</value>
                </underlyingSecurityTitle>
                <underlyingSecurityShares>
                    <value>18000</value>
                </underlyingSecurityShares>
            </underlyingSecurity>
            <ownershipNature>
                <directOrIndirectOwnership>
                    <value>D</value>
                </directOrIndirectOwnership>
                <natureOfOwnership>
                    <value></value>
                </natureOfOwnership>
            </ownershipNature>
        </derivativeHolding>
        <derivativeHolding>
            <securityTitle>
                <value>Stock Option (right to purchase)</value>
            </securityTitle>
            <conversionOrExercisePrice>
                <value>10.33</value>
            </conversionOrExercisePrice>
            <exerciseDate>
                <footnoteId id="F9"/>
            </exerciseDate>
            <expirationDate>
                <value>2017-09-27</value>
            </expirationDate>
            <underlyingSecurity>
                <underlyingSecurityTitle>
                    <value>Common Stoc,, $0.01, par value</value>
                </underlyingSecurityTitle>
                <underlyingSecurityShares>
                    <value>23800</value>
                </underlyingSecurityShares>
            </underlyingSecurity>
            <ownershipNature>
                <directOrIndirectOwnership>
                    <value>D</value>
                </directOrIndirectOwnership>
                <natureOfOwnership>
                    <value></value>
                </natureOfOwnership>
            </ownershipNature>
        </derivativeHolding>
    </derivativeTable>

    <footnotes>
        <footnote id="F1">This entry includes four grants of Performance Accelerated Restricted Stock Units (3,800 on 9/12/03; 2,300 on 9/29/05; 2,700 on 9/21/06 and 3,100 on 9/27/07) that vest 100% on the fifth anniversary of the grant date; vesting may be accelerated to the third or fourth anniversary of the grant date if certain performance milestones are met.</footnote>
        <footnote id="F2">Vesting of performance shares is based on the Company's achievement of certain ROIC targets with 825 vesting on the first day after the Company files its Form 10-K for the fiscal year ending April 27, 2008, if the ROIC target for that performance period is met; and 1,650 vesting on the first day after the Company files its Form 10-K for the fiscal year ending May 3, 2009, if the ROIC target for that performance period is met.  The vesting of the performance share award shall be accelerated to include cumulatively the next level(s) of vesting commensurate with the level of ROIC target achieved.  Because the vesting of the performance shares is tied to a performance measure that is not the Company's stock price, the performace shares are not currently considered &quot;derivative securities&quot; under applicable rules and accordingly the Reporting Person may be considered to have made this filing voluntarily.</footnote>
        <footnote id="F3">Performance shares either vest or forfeit on their respective vesting dates.</footnote>
        <footnote id="F4">Vesting of performance shares generally is based on the Company's achievement of certain ROIC targets with 25% vesting on the first day after the Company files its Form 10-K for the fiscal year ending April 27, 2008, if the ROIC target for that performance period is met; 25% vesting on the first day after the Company files its Form 10-K for the fiscal year ending May 3, 2009, if the ROIC target for that performance period is met; and 50% vesting on the first day after the Company files its Form 10-K for the fiscal year ending May 2, 2010, if the ROIC target for that performance period is met.  The vesting of the performance share award shall be accelerated to include cumulatively the next level(s) of vesting commensurate with the level of ROIC target achieved.  Because the vesting of the performance shares is tied to a performance measure that is not the Company's stock price, the performace shares are not currently considered &quot;derivative securities&quot; under applicable rules and accordingly the Reporting Person may be considered to have made this filing voluntarily.</footnote>
        <footnote id="F5">Vesting of performance shares generally is based on the Company's achievement of certain ROIC targets with 25% eligible to vest on the first day after the Company files its Form 10-K for the fiscal year ending May 3, 2009; 25% eligible to vest on the first day after the Company files its Form 10-K for the fiscal year ending May 2, 2010; and 50% eligible to vest on the first day after the Company files its Form 10-K for the fiscal year ending May 1, 2011.  The vesting of the performance share award shall be accelerated to include cumulatively the next level(s) of vesting commensurate with the level of ROIC target achieved.  Because the vesting of the performance shares is tied to a performance measure that is not the Company's stock price, the performance shares are not currently considered &quot;derivative securities&quot; under applicable rules and accordingly the Reporting Person may be considered to have reported these performance shares voluntarily.</footnote>
        <footnote id="F6">Number reported reflects maximum number of shares of common stock which may be earned.  The target number of shares associated with the grant is 5,100.  Vesting of performance share units is based on the Company's level of achievement of Relative Total Shareholder Return (RTSR) over the performance period (FY2009-FY2011).</footnote>
        <footnote id="F7">Performance share units either vest or forfeit based on the Company's level of achievement of RTSR over the performance period.  Because vesting of the performance share units is tied to a performance measure that is not solely the Company's stock price (due to the impact of Company dividends and comparator group performance on RTSR), the performance share units may not currently be considered &quot;derivative securities&quot; under applicable rules and accordingly, to such extent, the Reporting Person may be considered to have reported these performance share units voluntarily.</footnote>
        <footnote id="F8">Fully vested</footnote>
        <footnote id="F9">Vest 25% per year for four (4) years beginning with the first anniversary of the grant date (which date is 10 years prior to expiration date).</footnote>
    </footnotes>

    <remarks></remarks>

    <ownerSignature>
        <signatureName>Richard W. Muto</signatureName>
        <signatureDate>2008-07-02</signatureDate>
    </ownerSignature>
</ownershipDocument>
