<SUBMISSION>
<ACCESSION-NUMBER>0001181431-04-008691
<TYPE>5
<PUBLIC-DOCUMENT-COUNT>1
<PERIOD>20031231
<FILING-DATE>20040212
<ISSUER>
<COMPANY-DATA>
<CONFORMED-NAME>ENTERPRISE FINANCIAL SERVICES CORP
<CIK>0001025835
<ASSIGNED-SIC>6022
<IRS-NUMBER>431706259
<STATE-OF-INCORPORATION>DE
<FISCAL-YEAR-END>1231
</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>MARSH STEPHEN P
<CIK>0001264209
</OWNER-DATA>
<FILING-VALUES>
<FORM-TYPE>5
<ACT>34
<FILE-NUMBER>001-15373
<FILM-NUMBER>04591875
</FILING-VALUES>
<MAIL-ADDRESS>
<STREET1>150 N. MERAMEC
<CITY>CLAYTON
<STATE>MI
<ZIP>63105
</MAIL-ADDRESS>
</REPORTING-OWNER>
<DOCUMENT>
<TYPE>5
<SEQUENCE>1
<FILENAME>rrd32984.xml
<DESCRIPTION>MARSH-FORM 5
<TEXT>
<XML>
<?xml version="1.0"?>
<ownershipDocument>

    <schemaVersion>X0201</schemaVersion>

    <documentType>5</documentType>

    <periodOfReport>2003-12-31</periodOfReport>

    <notSubjectToSection16>0</notSubjectToSection16>

    <form3HoldingsReported>0</form3HoldingsReported>

    <form4TransactionsReported>0</form4TransactionsReported>

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

    <reportingOwner>
        <reportingOwnerId>
            <rptOwnerCik>0001264209</rptOwnerCik>
            <rptOwnerName>MARSH STEPHEN P</rptOwnerName>
        </reportingOwnerId>
        <reportingOwnerAddress>
            <rptOwnerStreet1>150 NORTH 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>President &amp; COO</officerTitle>
        </reportingOwnerRelationship>
    </reportingOwner>

    <derivativeTable>
        <derivativeHolding>
            <securityTitle>
                <value>CALL OPTION (RIGHT TO BUY)</value>
            </securityTitle>
            <conversionOrExercisePrice>
                <value>11.50</value>
            </conversionOrExercisePrice>
            <transactionCoding></transactionCoding>
            <exerciseDate>
                <value>2004-01-01</value>
            </exerciseDate>
            <expirationDate>
                <value>2004-02-15</value>
            </expirationDate>
            <underlyingSecurity>
                <underlyingSecurityTitle>
                    <value>COMMON STOCK</value>
                </underlyingSecurityTitle>
                <underlyingSecurityShares>
                    <value>7700</value>
                </underlyingSecurityShares>
            </underlyingSecurity>
            <postTransactionAmounts>
                <sharesOwnedFollowingTransaction>
                    <value>7700</value>
                </sharesOwnedFollowingTransaction>
            </postTransactionAmounts>
            <ownershipNature>
                <directOrIndirectOwnership>
                    <value>D</value>
                </directOrIndirectOwnership>
            </ownershipNature>
        </derivativeHolding>
        <derivativeHolding>
            <securityTitle>
                <value>INCENTIVE STOCK OPTION (RIGHT TO BUY)</value>
            </securityTitle>
            <conversionOrExercisePrice>
                <value>13.05</value>
            </conversionOrExercisePrice>
            <transactionCoding></transactionCoding>
            <exerciseDate>
                <value>2008-08-25</value>
            </exerciseDate>
            <expirationDate>
                <value>2013-08-25</value>
            </expirationDate>
            <underlyingSecurity>
                <underlyingSecurityTitle>
                    <value>COMMON STOCK</value>
                </underlyingSecurityTitle>
                <underlyingSecurityShares>
                    <value>25000</value>
                </underlyingSecurityShares>
            </underlyingSecurity>
            <postTransactionAmounts>
                <sharesOwnedFollowingTransaction>
                    <value>25000</value>
                </sharesOwnedFollowingTransaction>
            </postTransactionAmounts>
            <ownershipNature>
                <directOrIndirectOwnership>
                    <value>D</value>
                </directOrIndirectOwnership>
            </ownershipNature>
        </derivativeHolding>
    </derivativeTable>

    <ownerSignature>
        <signatureName>STEPHEN P. MARSH BY POWER OF ATTORNEY</signatureName>
        <signatureDate>2004-02-12</signatureDate>
    </ownerSignature>
</ownershipDocument>

</XML>
</TEXT>
</DOCUMENT>
</SUBMISSION>
