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Proc-Type: 2001,MIC-CLEAR
Originator-Name: webmaster@www.sec.gov
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MIC-Info: RSA-MD5,RSA,
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 Q8D8/UhvWWgg8ZdhE2fqBg==

<SEC-DOCUMENT>0001127602-10-014914.txt : 20100519
<SEC-HEADER>0001127602-10-014914.hdr.sgml : 20100519
<ACCEPTANCE-DATETIME>20100519172718
ACCESSION NUMBER:		0001127602-10-014914
CONFORMED SUBMISSION TYPE:	4
PUBLIC DOCUMENT COUNT:		1
CONFORMED PERIOD OF REPORT:	20100517
FILED AS OF DATE:		20100519
DATE AS OF CHANGE:		20100519

REPORTING-OWNER:	

	OWNER DATA:	
		COMPANY CONFORMED NAME:			WADE JEFFREY L
		CENTRAL INDEX KEY:			0001225767

	FILING VALUES:
		FORM TYPE:		4
		SEC ACT:		1934 Act
		SEC FILE NUMBER:	000-30111
		FILM NUMBER:		10846044

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

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
</SEC-HEADER>
<DOCUMENT>
<TYPE>4
<SEQUENCE>1
<FILENAME>form4.xml
<DESCRIPTION>PRIMARY DOCUMENT
<TEXT>
<XML>
<?xml version="1.0"?>
<ownershipDocument>

    <schemaVersion>X0303</schemaVersion>

    <documentType>4</documentType>

    <periodOfReport>2010-05-17</periodOfReport>

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

    <reportingOwner>
        <reportingOwnerId>
            <rptOwnerCik>0001225767</rptOwnerCik>
            <rptOwnerName>WADE JEFFREY L</rptOwnerName>
        </reportingOwnerId>
        <reportingOwnerAddress>
            <rptOwnerStreet1>8800 TECHNOLOGY FOREST PLACE</rptOwnerStreet1>
            <rptOwnerStreet2></rptOwnerStreet2>
            <rptOwnerCity>THE WOODLANDS</rptOwnerCity>
            <rptOwnerState>TX</rptOwnerState>
            <rptOwnerZipCode>77381</rptOwnerZipCode>
            <rptOwnerStateDescription></rptOwnerStateDescription>
        </reportingOwnerAddress>
        <reportingOwnerRelationship>
            <isOfficer>1</isOfficer>
            <officerTitle>EVP, Corp Dev and CFO</officerTitle>
        </reportingOwnerRelationship>
    </reportingOwner>

    <derivativeTable>
        <derivativeTransaction>
            <securityTitle>
                <value>Stock Option (Right to Buy)</value>
            </securityTitle>
            <conversionOrExercisePrice>
                <value>1.52</value>
            </conversionOrExercisePrice>
            <transactionDate>
                <value>2010-05-17</value>
            </transactionDate>
            <transactionCoding>
                <transactionFormType>4</transactionFormType>
                <transactionCode>A</transactionCode>
                <equitySwapInvolved>0</equitySwapInvolved>
            </transactionCoding>
            <transactionTimeliness></transactionTimeliness>
            <transactionAmounts>
                <transactionShares>
                    <value>100000</value>
                </transactionShares>
                <transactionPricePerShare>
                    <value>0</value>
                </transactionPricePerShare>
                <transactionAcquiredDisposedCode>
                    <value>A</value>
                </transactionAcquiredDisposedCode>
            </transactionAmounts>
            <exerciseDate>
                <footnoteId id="F1"/>
            </exerciseDate>
            <expirationDate>
                <value>2020-05-17</value>
            </expirationDate>
            <underlyingSecurity>
                <underlyingSecurityTitle>
                    <value>Common Stock</value>
                </underlyingSecurityTitle>
                <underlyingSecurityShares>
                    <value>100000</value>
                </underlyingSecurityShares>
            </underlyingSecurity>
            <postTransactionAmounts>
                <sharesOwnedFollowingTransaction>
                    <value>100000</value>
                </sharesOwnedFollowingTransaction>
            </postTransactionAmounts>
            <ownershipNature>
                <directOrIndirectOwnership>
                    <value>D</value>
                </directOrIndirectOwnership>
            </ownershipNature>
        </derivativeTransaction>
    </derivativeTable>

    <footnotes>
        <footnote id="F1">Option vests with respect to 25% of the shares subject to the option on the first anniversary of grant (5/17/2011) and vests 1/48th per month for each month of service thereafter.</footnote>
    </footnotes>

    <ownerSignature>
        <signatureName>/s/ Jeffrey L. Wade</signatureName>
        <signatureDate>2010-05-19</signatureDate>
    </ownerSignature>
</ownershipDocument>
</XML>
</TEXT>
</DOCUMENT>
</SEC-DOCUMENT>
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