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Proc-Type: 2001,MIC-CLEAR
Originator-Name: webmaster@www.sec.gov
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MIC-Info: RSA-MD5,RSA,
 QyY8YCBw/VF4Zkwcoe1pJ0TiDP88lDxjyGil5jJBn4i72D3+mnbJMaArT4rBBdgS
 ELLJZ3ieF71AZyv3xay3TA==

<SEC-DOCUMENT>0001062822-07-000054.txt : 20070926
<SEC-HEADER>0001062822-07-000054.hdr.sgml : 20070926
<ACCEPTANCE-DATETIME>20070926163323
ACCESSION NUMBER:		0001062822-07-000054
CONFORMED SUBMISSION TYPE:	3
PUBLIC DOCUMENT COUNT:		1
CONFORMED PERIOD OF REPORT:	20070924
FILED AS OF DATE:		20070926
DATE AS OF CHANGE:		20070926

ISSUER:		

	COMPANY DATA:	
		COMPANY CONFORMED NAME:			LEXICON PHARMACEUTICALS, INC./DE
		CENTRAL INDEX KEY:			0001062822
		STANDARD INDUSTRIAL CLASSIFICATION:	PHARMACEUTICAL PREPARATIONS [2834]
		IRS NUMBER:				760474169
		STATE OF INCORPORATION:			DE
		FISCAL YEAR END:			1231

	BUSINESS ADDRESS:	
		STREET 1:		8800 TECHNOLOGY FOREST PLACE
		CITY:			THE WOODLANDS
		STATE:			TX
		ZIP:			77381
		BUSINESS PHONE:		2818633000

	MAIL ADDRESS:	
		STREET 1:		8800 TECHNOLOGY FOREST PLACE
		CITY:			THE WOODLANDS
		STATE:			TX
		ZIP:			77381

	FORMER COMPANY:	
		FORMER CONFORMED NAME:	LEXICON GENETICS INC/TX
		DATE OF NAME CHANGE:	20000126

REPORTING-OWNER:	

	OWNER DATA:	
		COMPANY CONFORMED NAME:			Swain Judith L
		CENTRAL INDEX KEY:			0001413573

	FILING VALUES:
		FORM TYPE:		3
		SEC ACT:		1934 Act
		SEC FILE NUMBER:	000-30111
		FILM NUMBER:		071136884

	BUSINESS ADDRESS:	
		BUSINESS PHONE:		281-863-3000

	MAIL ADDRESS:	
		STREET 1:		8800 TECHNOLOGY FOREST PLACE
		CITY:			THE WOODLANDS
		STATE:			TX
		ZIP:			77381
</SEC-HEADER>
<DOCUMENT>
<TYPE>3
<SEQUENCE>1
<FILENAME>swa310.xml
<TEXT>
<XML>
<?xml version="1.0"?>
<ownershipDocument>

    <schemaVersion>X0202</schemaVersion>

    <documentType>3</documentType>

    <periodOfReport>2007-09-24</periodOfReport>

    <noSecuritiesOwned>1</noSecuritiesOwned>

    <issuer>
        <issuerCik>0001062822</issuerCik>
        <issuerName>LEXICON PHARMACEUTICALS, INC./DE</issuerName>
        <issuerTradingSymbol>LXRX</issuerTradingSymbol>
    </issuer>

    <reportingOwner>
        <reportingOwnerId>
            <rptOwnerCik>0001413573</rptOwnerCik>
            <rptOwnerName>Swain Judith L</rptOwnerName>
        </reportingOwnerId>
        <reportingOwnerAddress>
            <rptOwnerStreet1>8800 TECHNOLOGY FOREST PLACE</rptOwnerStreet1>
            <rptOwnerStreet2></rptOwnerStreet2>
            <rptOwnerCity>THE WOODLANDS</rptOwnerCity>
            <rptOwnerState>TX</rptOwnerState>
            <rptOwnerZipCode>773811160</rptOwnerZipCode>
            <rptOwnerStateDescription></rptOwnerStateDescription>
        </reportingOwnerAddress>
        <reportingOwnerRelationship>
            <isDirector>1</isDirector>
            <isOfficer>0</isOfficer>
            <isTenPercentOwner>0</isTenPercentOwner>
            <isOther>0</isOther>
        </reportingOwnerRelationship>
    </reportingOwner>

    <footnotes></footnotes>

    <ownerSignature>
        <signatureName>/s/ Swain, Judith L.</signatureName>
        <signatureDate>2007-09-25</signatureDate>
    </ownerSignature>
</ownershipDocument>
</XML>
</TEXT>
</DOCUMENT>
</SEC-DOCUMENT>
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