-----BEGIN PRIVACY-ENHANCED MESSAGE-----
Proc-Type: 2001,MIC-CLEAR
Originator-Name: webmaster@www.sec.gov
Originator-Key-Asymmetric:
 MFgwCgYEVQgBAQICAf8DSgAwRwJAW2sNKK9AVtBzYZmr6aGjlWyK3XmZv3dTINen
 TWSM7vrzLADbmYQaionwg5sDW3P6oaM5D3tdezXMm7z1T+B+twIDAQAB
MIC-Info: RSA-MD5,RSA,
 U+Occsgym7XD08X+aN53FHHoyvHiWIzW9WQZxDzkTbx7KxVkIavs1TUpYiVZn5yS
 iVhB3NORNu/gqPhqBnejCQ==

<SEC-DOCUMENT>0001140361-07-007050.txt : 20070403
<SEC-HEADER>0001140361-07-007050.hdr.sgml : 20070403
<ACCEPTANCE-DATETIME>20070403165826
ACCESSION NUMBER:		0001140361-07-007050
CONFORMED SUBMISSION TYPE:	4
PUBLIC DOCUMENT COUNT:		1
CONFORMED PERIOD OF REPORT:	20070331
FILED AS OF DATE:		20070403
DATE AS OF CHANGE:		20070403

ISSUER:		

	COMPANY DATA:	
		COMPANY CONFORMED NAME:			EXPRESS SCRIPTS INC
		CENTRAL INDEX KEY:			0000885721
		STANDARD INDUSTRIAL CLASSIFICATION:	RETAIL-DRUG STORES AND PROPRIETARY STORES [5912]
		IRS NUMBER:				431420563
		STATE OF INCORPORATION:			DE
		FISCAL YEAR END:			1231

	BUSINESS ADDRESS:	
		STREET 1:		13900 REIVERPORT DRIVE
		CITY:			MARYLAND HEIGHTS
		STATE:			MO
		ZIP:			63043
		BUSINESS PHONE:		3147701666

	MAIL ADDRESS:	
		STREET 1:		13900 REIVERPORT DRIVE
		CITY:			MARYLAND HEIGHTS
		STATE:			MO
		ZIP:			63043

REPORTING-OWNER:	

	OWNER DATA:	
		COMPANY CONFORMED NAME:			STIFTEN EDWARD J
		CENTRAL INDEX KEY:			0001285538

	FILING VALUES:
		FORM TYPE:		4
		SEC ACT:		1934 Act
		SEC FILE NUMBER:	000-20199
		FILM NUMBER:		07745213

	MAIL ADDRESS:	
		STREET 1:		13900 RIVERPORT DRIVE
		CITY:			MARYLAND HEIGHT
		STATE:			MO
		ZIP:			63043
</SEC-HEADER>
<DOCUMENT>
<TYPE>4
<SEQUENCE>1
<FILENAME>doc1.xml
<DESCRIPTION>FORM 4
<TEXT>
<XML>
<?xml version="1.0"?>
<ownershipDocument>

    <schemaVersion>X0202</schemaVersion>

    <documentType>4</documentType>

    <periodOfReport>2007-03-31</periodOfReport>

    <notSubjectToSection16>0</notSubjectToSection16>

    <issuer>
        <issuerCik>0000885721</issuerCik>
        <issuerName>EXPRESS SCRIPTS INC</issuerName>
        <issuerTradingSymbol>ESRX</issuerTradingSymbol>
    </issuer>

    <reportingOwner>
        <reportingOwnerId>
            <rptOwnerCik>0001285538</rptOwnerCik>
            <rptOwnerName>STIFTEN EDWARD J</rptOwnerName>
        </reportingOwnerId>
        <reportingOwnerAddress>
            <rptOwnerStreet1>C/O EXPRESS SCRIPTS, INC.</rptOwnerStreet1>
            <rptOwnerStreet2>13900 RIVERPORT DRIVE</rptOwnerStreet2>
            <rptOwnerCity>MARYLAND HEIGHTS</rptOwnerCity>
            <rptOwnerState>MO</rptOwnerState>
            <rptOwnerZipCode>63043</rptOwnerZipCode>
            <rptOwnerStateDescription></rptOwnerStateDescription>
        </reportingOwnerAddress>
        <reportingOwnerRelationship>
            <isDirector>0</isDirector>
            <isOfficer>1</isOfficer>
            <isTenPercentOwner>0</isTenPercentOwner>
            <isOther>0</isOther>
            <officerTitle>Senior VP &amp;  CFO</officerTitle>
            <otherText></otherText>
        </reportingOwnerRelationship>
    </reportingOwner>

    <nonDerivativeTable>
        <nonDerivativeTransaction>
            <securityTitle>
                <value>Common Stock</value>
            </securityTitle>
            <transactionDate>
                <value>2007-03-31</value>
            </transactionDate>
            <deemedExecutionDate></deemedExecutionDate>
            <transactionCoding>
                <transactionFormType>4</transactionFormType>
                <transactionCode>D</transactionCode>
                <equitySwapInvolved>0</equitySwapInvolved>
            </transactionCoding>
            <transactionTimeliness>
                <value></value>
            </transactionTimeliness>
            <transactionAmounts>
                <transactionShares>
                    <value>6208</value>
                    <footnoteId id="F1"/>
                </transactionShares>
                <transactionPricePerShare>
                    <value>80.72</value>
                </transactionPricePerShare>
                <transactionAcquiredDisposedCode>
                    <value>D</value>
                </transactionAcquiredDisposedCode>
            </transactionAmounts>
            <postTransactionAmounts>
                <sharesOwnedFollowingTransaction>
                    <value>39887</value>
                </sharesOwnedFollowingTransaction>
            </postTransactionAmounts>
            <ownershipNature>
                <directOrIndirectOwnership>
                    <value>D</value>
                </directOrIndirectOwnership>
                <natureOfOwnership>
                    <value></value>
                </natureOfOwnership>
            </ownershipNature>
        </nonDerivativeTransaction>
    </nonDerivativeTable>

    <footnotes>
        <footnote id="F1">Represents shares tendered to Express Scripts, Inc. to cover Mr. Stiften?s tax liability due upon lapse of restrictions of restricted stock previously awarded under Express Scripts, Inc. 2000 Long Term Incentive Plan.</footnote>
    </footnotes>

    <remarks></remarks>

    <ownerSignature>
        <signatureName>Edward Stiften</signatureName>
        <signatureDate>2007-04-03</signatureDate>
    </ownerSignature>
</ownershipDocument>
</XML>
</TEXT>
</DOCUMENT>
</SEC-DOCUMENT>
-----END PRIVACY-ENHANCED MESSAGE-----