<SUBMISSION>
<ACCESSION-NUMBER>0001025835-08-000026
<TYPE>5
<PUBLIC-DOCUMENT-COUNT>1
<PERIOD>20071231
<FILING-DATE>20080131
<DATE-OF-FILING-DATE-CHANGE>20080131
<ISSUER>
<COMPANY-DATA>
<CONFORMED-NAME>ENTERPRISE FINANCIAL SERVICES CORP
<CIK>0001025835
<ASSIGNED-SIC>6022
<IRS-NUMBER>431706259
<STATE-OF-INCORPORATION>DE
<FISCAL-YEAR-END>0907
</COMPANY-DATA>
<BUSINESS-ADDRESS>
<STREET1>150 NORTH MERAMEC
<STREET2>150 NORTH MERAMEC
<CITY>CLAYTON
<STATE>MO
<ZIP>63105
<PHONE>3147255500
</BUSINESS-ADDRESS>
<MAIL-ADDRESS>
<STREET1>150 NORTH MERAMEC
<STREET2>150 NORTH MERAMEC
<CITY>CLAYTON
<STATE>MO
<ZIP>63105
</MAIL-ADDRESS>
<FORMER-COMPANY>
<FORMER-CONFORMED-NAME>ENTERBANK HOLDINGS INC
<DATE-CHANGED>19961024
</FORMER-COMPANY>
</ISSUER>
<REPORTING-OWNER>
<OWNER-DATA>
<CONFORMED-NAME>BARSTOW DEBORAH N
<CIK>0001325343
</OWNER-DATA>
<FILING-VALUES>
<FORM-TYPE>5
<ACT>34
<FILE-NUMBER>001-15373
<FILM-NUMBER>08563890
</FILING-VALUES>
<BUSINESS-ADDRESS>
<PHONE>314-725-5500
</BUSINESS-ADDRESS>
<MAIL-ADDRESS>
<STREET1>150 N MERAMEC
<CITY>CLAYTON
<STATE>MO
<ZIP>63105
</MAIL-ADDRESS>
</REPORTING-OWNER>
<DOCUMENT>
<TYPE>5
<SEQUENCE>1
<FILENAME>edgar.xml
<DESCRIPTION>PRIMARY DOCUMENT
<TEXT>
<XML>
<?xml version="1.0"?>
<ownershipDocument>

    <schemaVersion>X0202</schemaVersion>

    <documentType>5</documentType>

    <periodOfReport>2007-12-31</periodOfReport>

    <form3HoldingsReported>0</form3HoldingsReported>

    <form4TransactionsReported>0</form4TransactionsReported>

    <issuer>
        <issuerCik>0001025835</issuerCik>
        <issuerName>ENTERPRISE FINANCIAL SERVICES CORP</issuerName>
        <issuerTradingSymbol>EFSC</issuerTradingSymbol>
    </issuer>

    <reportingOwner>
        <reportingOwnerId>
            <rptOwnerCik>0001325343</rptOwnerCik>
            <rptOwnerName>BARSTOW DEBORAH N</rptOwnerName>
        </reportingOwnerId>
        <reportingOwnerAddress>
            <rptOwnerStreet1>150 N. MERAMEC</rptOwnerStreet1>
            <rptOwnerStreet2></rptOwnerStreet2>
            <rptOwnerCity>ST. LOUIS</rptOwnerCity>
            <rptOwnerState>MO</rptOwnerState>
            <rptOwnerZipCode>63105</rptOwnerZipCode>
            <rptOwnerStateDescription></rptOwnerStateDescription>
        </reportingOwnerAddress>
        <reportingOwnerRelationship>
            <isDirector>0</isDirector>
            <isOfficer>1</isOfficer>
            <isTenPercentOwner>0</isTenPercentOwner>
            <isOther>0</isOther>
            <officerTitle>SVP &amp; Controller</officerTitle>
        </reportingOwnerRelationship>
    </reportingOwner>

    <nonDerivativeTable>
        <nonDerivativeHolding>
            <securityTitle>
                <value>Common Stock</value>
            </securityTitle>
            <postTransactionAmounts>
                <sharesOwnedFollowingTransaction>
                    <value>6671</value>
                </sharesOwnedFollowingTransaction>
            </postTransactionAmounts>
            <ownershipNature>
                <directOrIndirectOwnership>
                    <value>D</value>
                </directOrIndirectOwnership>
                <natureOfOwnership>
                    <value></value>
                </natureOfOwnership>
            </ownershipNature>
        </nonDerivativeHolding>
        <nonDerivativeHolding>
            <securityTitle>
                <value>Common Stock</value>
            </securityTitle>
            <postTransactionAmounts>
                <sharesOwnedFollowingTransaction>
                    <value>1100</value>
                    <footnoteId id="F1"/>
                </sharesOwnedFollowingTransaction>
            </postTransactionAmounts>
            <ownershipNature>
                <directOrIndirectOwnership>
                    <value>D</value>
                </directOrIndirectOwnership>
                <natureOfOwnership>
                    <value></value>
                </natureOfOwnership>
            </ownershipNature>
        </nonDerivativeHolding>
    </nonDerivativeTable>

    <derivativeTable>
        <derivativeHolding>
            <securityTitle>
                <value>Incentive Stock Option (right to buy)</value>
            </securityTitle>
            <conversionOrExercisePrice>
                <value>12.50</value>
            </conversionOrExercisePrice>
            <exerciseDate>
                <value>2004-10-01</value>
            </exerciseDate>
            <expirationDate>
                <value>2013-01-01</value>
            </expirationDate>
            <underlyingSecurity>
                <underlyingSecurityTitle>
                    <value>Common Stock</value>
                </underlyingSecurityTitle>
                <underlyingSecurityShares>
                    <value>4000</value>
                </underlyingSecurityShares>
            </underlyingSecurity>
            <postTransactionAmounts>
                <sharesOwnedFollowingTransaction>
                    <value>4000</value>
                </sharesOwnedFollowingTransaction>
            </postTransactionAmounts>
            <ownershipNature>
                <directOrIndirectOwnership>
                    <value>D</value>
                </directOrIndirectOwnership>
                <natureOfOwnership>
                    <value></value>
                </natureOfOwnership>
            </ownershipNature>
        </derivativeHolding>
        <derivativeHolding>
            <securityTitle>
                <value>Incentive Stock Option (right to buy)</value>
            </securityTitle>
            <conversionOrExercisePrice>
                <value>13.10</value>
            </conversionOrExercisePrice>
            <exerciseDate>
                <value>2004-10-01</value>
            </exerciseDate>
            <expirationDate>
                <value>2013-08-01</value>
            </expirationDate>
            <underlyingSecurity>
                <underlyingSecurityTitle>
                    <value>Common Stock</value>
                </underlyingSecurityTitle>
                <underlyingSecurityShares>
                    <value>2000</value>
                </underlyingSecurityShares>
            </underlyingSecurity>
            <postTransactionAmounts>
                <sharesOwnedFollowingTransaction>
                    <value>2000</value>
                </sharesOwnedFollowingTransaction>
            </postTransactionAmounts>
            <ownershipNature>
                <directOrIndirectOwnership>
                    <value>D</value>
                </directOrIndirectOwnership>
                <natureOfOwnership>
                    <value></value>
                </natureOfOwnership>
            </ownershipNature>
        </derivativeHolding>
        <derivativeHolding>
            <securityTitle>
                <value>Restricted Share Units</value>
            </securityTitle>
            <conversionOrExercisePrice>
                <footnoteId id="F2"/>
            </conversionOrExercisePrice>
            <exerciseDate>
                <footnoteId id="F3"/>
            </exerciseDate>
            <expirationDate>
                <footnoteId id="F3"/>
            </expirationDate>
            <underlyingSecurity>
                <underlyingSecurityTitle>
                    <value>Common Stock</value>
                </underlyingSecurityTitle>
                <underlyingSecurityShares>
                    <value>1514</value>
                </underlyingSecurityShares>
            </underlyingSecurity>
            <postTransactionAmounts>
                <sharesOwnedFollowingTransaction>
                    <value>1514</value>
                </sharesOwnedFollowingTransaction>
            </postTransactionAmounts>
            <ownershipNature>
                <directOrIndirectOwnership>
                    <value>D</value>
                </directOrIndirectOwnership>
                <natureOfOwnership>
                    <value></value>
                </natureOfOwnership>
            </ownershipNature>
        </derivativeHolding>
        <derivativeHolding>
            <securityTitle>
                <value>Stock Settled Stock Appreciation Rights</value>
            </securityTitle>
            <conversionOrExercisePrice>
                <value>25.63</value>
            </conversionOrExercisePrice>
            <exerciseDate>
                <value>2007-12-15</value>
                <footnoteId id="F4"/>
            </exerciseDate>
            <expirationDate>
                <value>2017-06-15</value>
            </expirationDate>
            <underlyingSecurity>
                <underlyingSecurityTitle>
                    <value>Common Stock</value>
                </underlyingSecurityTitle>
                <underlyingSecurityShares>
                    <value>2500</value>
                </underlyingSecurityShares>
            </underlyingSecurity>
            <postTransactionAmounts>
                <sharesOwnedFollowingTransaction>
                    <value>2500</value>
                </sharesOwnedFollowingTransaction>
            </postTransactionAmounts>
            <ownershipNature>
                <directOrIndirectOwnership>
                    <value>D</value>
                </directOrIndirectOwnership>
                <natureOfOwnership>
                    <value></value>
                </natureOfOwnership>
            </ownershipNature>
        </derivativeHolding>
    </derivativeTable>

    <footnotes>
        <footnote id="F1">These shares are held jointly with spouse.</footnote>
        <footnote id="F2">The RSUs were granted pursuant to the Company's 2002 Stock Incentive Plan.  Each RSU represents the right to receive one share of Common Stock, subject to adjustment as provided in the Grant Agreement.</footnote>
        <footnote id="F3">The RSUs vest at a rate of 20% annually over five years, subject to continued employment of the reporting person.  Vesting occurs on December 15 of each year, commencing in the calendar year of the grant.  On each vesting date, for each RSU vesting on such date, the reporting person will receive one share of Common Stock.</footnote>
        <footnote id="F4">Each SSAR consists of the right to receive an amount, in common stock, equal to the excess of the fair market value of a share of common stock on the date of exercise over the exercise price of the SSAR.  The SSARs vest at a rate of 20% annually over five years, subject to continued employement of the reporting person.  Vesting occurs on December 15 of each year, commencing December 15, 2007.</footnote>
    </footnotes>

    <remarks></remarks>

    <ownerSignature>
        <signatureName>Deborah N. Barstow</signatureName>
        <signatureDate>2008-01-31</signatureDate>
    </ownerSignature>
</ownershipDocument>
</XML>
</TEXT>
</DOCUMENT>
</SUBMISSION>
