<?xml version="1.0"?><ownershipDocument><schemaVersion>X0201</schemaVersion>    <documentType>4</documentType><periodOfReport>2003-12-18</periodOfReport><notSubjectToSection16>1</notSubjectToSection16><issuer><issuerCik>0000930885</issuerCik><issuerName>DOCUMENTUM INC</issuerName>        <issuerTradingSymbol>DCTM</issuerTradingSymbol></issuer><reportingOwner><reportingOwnerId><rptOwnerCik>0001246207</rptOwnerCik><rptOwnerName>DE CESARE MICHAEL P</rptOwnerName></reportingOwnerId><reportingOwnerAddress><rptOwnerStreet1>6801 KOLL CENTER PARKWAY</rptOwnerStreet1><rptOwnerStreet2></rptOwnerStreet2><rptOwnerCity>PLEASANTON</rptOwnerCity><rptOwnerState>CA</rptOwnerState><rptOwnerZipCode>94566-7047</rptOwnerZipCode><rptOwnerStateDescription></rptOwnerStateDescription></reportingOwnerAddress><reportingOwnerRelationship><isDirector>0</isDirector><isOfficer>1</isOfficer><isTenPercentOwner>0</isTenPercentOwner><isOther>0</isOther><officerTitle>EVP Worldwide Field Operations</officerTitle></reportingOwnerRelationship></reportingOwner><nonDerivativeTable><nonDerivativeTransaction><securityTitle><value>Common Stock</value></securityTitle><transactionDate><value>2003-12-18</value></transactionDate><deemedExecutionDate></deemedExecutionDate><transactionCoding><transactionFormType>4</transactionFormType><transactionCode>D</transactionCode><equitySwapInvolved>0</equitySwapInvolved></transactionCoding><transactionTimeliness><value></value></transactionTimeliness><transactionAmounts><transactionShares><value>3161.0000</value><footnoteId id="F1" /></transactionShares><transactionPricePerShare><value>0</value><footnoteId id="F2" /></transactionPricePerShare><transactionAcquiredDisposedCode><value>D</value></transactionAcquiredDisposedCode></transactionAmounts><postTransactionAmounts><sharesOwnedFollowingTransaction><value>0</value></sharesOwnedFollowingTransaction></postTransactionAmounts><ownershipNature><directOrIndirectOwnership><value>D</value></directOrIndirectOwnership></ownershipNature></nonDerivativeTransaction></nonDerivativeTable><derivativeTable><derivativeTransaction><securityTitle><value>Option to Buy Common Stock</value></securityTitle><conversionOrExercisePrice><value>18.5200</value></conversionOrExercisePrice><transactionDate><value>2003-12-18</value></transactionDate><deemedExecutionDate></deemedExecutionDate><transactionCoding><transactionFormType>4</transactionFormType><transactionCode>D</transactionCode><equitySwapInvolved>0</equitySwapInvolved></transactionCoding><transactionTimeliness><value></value></transactionTimeliness><transactionAmounts><transactionShares><value>250000.0000</value></transactionShares><transactionPricePerShare><value>0</value><footnoteId id="F3" /></transactionPricePerShare><transactionAcquiredDisposedCode><value>D</value></transactionAcquiredDisposedCode></transactionAmounts><exerciseDate><value>2002-12-20</value><footnoteId id="F3" /></exerciseDate><expirationDate><value>2001-12-20</value></expirationDate><underlyingSecurity><underlyingSecurityTitle><value>Common Stock</value></underlyingSecurityTitle><underlyingSecurityShares><value>250000.0000</value></underlyingSecurityShares></underlyingSecurity><postTransactionAmounts><sharesOwnedFollowingTransaction><value>0</value></sharesOwnedFollowingTransaction></postTransactionAmounts><ownershipNature><directOrIndirectOwnership><value>D</value></directOrIndirectOwnership></ownershipNature></derivativeTransaction><derivativeTransaction><securityTitle><value>Option to Buy Common Stock</value></securityTitle><conversionOrExercisePrice><value>14.1600</value></conversionOrExercisePrice><transactionDate><value>2003-12-18</value></transactionDate><deemedExecutionDate></deemedExecutionDate><transactionCoding><transactionFormType>4</transactionFormType><transactionCode>D</transactionCode><equitySwapInvolved>0</equitySwapInvolved></transactionCoding><transactionTimeliness><value></value></transactionTimeliness><transactionAmounts><transactionShares><value>50000.0000</value></transactionShares><transactionPricePerShare><value>0</value><footnoteId id="F4" /></transactionPricePerShare><transactionAcquiredDisposedCode><value>D</value></transactionAcquiredDisposedCode></transactionAmounts><exerciseDate><value>2003-10-24</value><footnoteId id="F4" /></exerciseDate><expirationDate><value>2012-10-24</value></expirationDate><underlyingSecurity><underlyingSecurityTitle><value>Common Stock</value></underlyingSecurityTitle><underlyingSecurityShares><value>50000.0000</value></underlyingSecurityShares></underlyingSecurity><postTransactionAmounts><sharesOwnedFollowingTransaction><value>0</value></sharesOwnedFollowingTransaction></postTransactionAmounts><ownershipNature><directOrIndirectOwnership><value>D</value></directOrIndirectOwnership></ownershipNature></derivativeTransaction><derivativeTransaction><securityTitle><value>Option to Buy Common Stock</value></securityTitle><conversionOrExercisePrice><value>28.9500</value></conversionOrExercisePrice><transactionDate><value>2003-12-18</value></transactionDate><deemedExecutionDate></deemedExecutionDate><transactionCoding><transactionFormType>4</transactionFormType><transactionCode>D</transactionCode><equitySwapInvolved>0</equitySwapInvolved></transactionCoding><transactionTimeliness><value></value></transactionTimeliness><transactionAmounts><transactionShares><value>50000.0000</value></transactionShares><transactionPricePerShare><value>0</value><footnoteId id="F5" /></transactionPricePerShare><transactionAcquiredDisposedCode><value>D</value></transactionAcquiredDisposedCode></transactionAmounts><exerciseDate><value>2004-10-21</value><footnoteId id="F5" /></exerciseDate><expirationDate><value>2013-10-21</value></expirationDate><underlyingSecurity><underlyingSecurityTitle><value>Common Stock</value></underlyingSecurityTitle><underlyingSecurityShares><value>50000.0000</value></underlyingSecurityShares></underlyingSecurity><postTransactionAmounts><sharesOwnedFollowingTransaction><value>0</value></sharesOwnedFollowingTransaction></postTransactionAmounts><ownershipNature><directOrIndirectOwnership><value>D</value></directOrIndirectOwnership></ownershipNature></derivativeTransaction></derivativeTable><footnotes><footnote id="F1">Amount of Securities Beneficially Owned at End of Month reflects shares acquired pursuant to purchases under the Company's IRS Code Section 423 Employee Stock Purchase Plan.</footnote><footnote id="F2">Disposed of pursuant to merger agreement between issuer and EMC Corporation in exchange for (i)6,875 shares of EMC common stock having a market value of $12.85 per share on effective date of merger plus approximately $2.25 of cash in lieu for fractional share.</footnote><footnote id="F3">This option which provided for monthly vesting beginning 12/20/02, was assumed by EMC in the merger and replaced with an option to purchase 543,750 shares of EMC for $8.52 per share. </footnote><footnote id="F4">This option which provided for monthly vesting beginning 10/24/03, was assumed by EMC in the merger and replaced with an option to purchase 108,750 shares of EMC for $6.52 per share</footnote><footnote id="F5">This option which provides for monthly vesting beginning 10/21/04, was assumed by EMC in the merger and replaced with an option to purchase 108,750 shares of EMC for $13.32 per share </footnote></footnotes><remarks></remarks><ownerSignature><signatureName>Sayed Darwish as Attorney in Fact for Michael DeCesare</signatureName><signatureDate>2003-12-22</signatureDate></ownerSignature></ownershipDocument>

