<SUBMISSION>
<ACCESSION-NUMBER>0001062822-03-000008
<TYPE>4
<PUBLIC-DOCUMENT-COUNT>1
<PERIOD>20031224
<FILING-DATE>20031229
<REPORTING-OWNER>
<OWNER-DATA>
<CONFORMED-NAME>PIGGOTT JAMES R PHD
<CIK>0001226356
</OWNER-DATA>
<FILING-VALUES>
<FORM-TYPE>4
<ACT>34
<FILE-NUMBER>000-30111
<FILM-NUMBER>031075086
</FILING-VALUES>
<MAIL-ADDRESS>
<STREET1>8800 TECHNOLOGY FOREST PLACE
<STREET2>C/O LEXICON GENETICS INC
<CITY>WOODLANDS
<STATE>TX
<ZIP>77381
</MAIL-ADDRESS>
</REPORTING-OWNER>
<ISSUER>
<COMPANY-DATA>
<CONFORMED-NAME>LEXICON GENETICS INC/TX
<CIK>0001062822
<ASSIGNED-SIC>2835
<IRS-NUMBER>760474169
<STATE-OF-INCORPORATION>DE
<FISCAL-YEAR-END>1231
</COMPANY-DATA>
<BUSINESS-ADDRESS>
<STREET1>8800 TECHNOLOGY FOREST PLACE
<CITY>THE WOODLANDS
<STATE>TX
<ZIP>77381
<PHONE>2818633000
</BUSINESS-ADDRESS>
<MAIL-ADDRESS>
<STREET1>8800 TECHNOLOGY FOREST PLACE
<CITY>THE WOODLANDS
<STATE>TX
<ZIP>77381
</MAIL-ADDRESS>
</ISSUER>
<DOCUMENT>
<TYPE>4
<SEQUENCE>1
<FILENAME>pig178.xml
<TEXT>
<XML>
<?xml version="1.0"?>
<ownershipDocument>
    <schemaVersion>X0201</schemaVersion>

    <documentType>4</documentType>
	<periodOfReport>2003-12-24</periodOfReport>
	<notSubjectToSection16>0</notSubjectToSection16>
    <issuer>
        <issuerCik>0001062822</issuerCik>
        <issuerName>LEXICON GENETICS INC/TX</issuerName>
        <issuerTradingSymbol>LEXG</issuerTradingSymbol>
	</issuer>
	<reportingOwner>
        <reportingOwnerId>
            <rptOwnerCik>0001226356</rptOwnerCik>
            <rptOwnerName>PIGGOTT JAMES R PHD</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>0</isDirector>
			<isOfficer>1</isOfficer>
			<isTenPercentOwner>0</isTenPercentOwner>
			<isOther>0</isOther>
			<officerTitle>Sr VP of Pharm</officerTitle>
		</reportingOwnerRelationship>
	</reportingOwner>
	<nonDerivativeTable>
		<nonDerivativeTransaction>
			<securityTitle>
				<value>Common Stock</value>
			</securityTitle>
			<transactionDate>
				<value>2003-12-24</value>
			</transactionDate>
			<deemedExecutionDate>
			</deemedExecutionDate>
			<transactionCoding>
				<transactionFormType>4</transactionFormType>
				<transactionCode>M</transactionCode>
				<equitySwapInvolved>0</equitySwapInvolved>
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			<transactionAmounts>
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				<transactionPricePerShare>
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				</transactionPricePerShare>
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				</transactionAcquiredDisposedCode>
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			<postTransactionAmounts>
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				</sharesOwnedFollowingTransaction>
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			<ownershipNature>
				<directOrIndirectOwnership>
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			<transactionAmounts>
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					<value>8800</value>
				</transactionShares>
				<transactionPricePerShare>
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				</transactionPricePerShare>
				<transactionAcquiredDisposedCode>
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				</transactionAcquiredDisposedCode>
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			<postTransactionAmounts>
				<sharesOwnedFollowingTransaction>
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				</sharesOwnedFollowingTransaction>
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			<ownershipNature>
				<directOrIndirectOwnership>
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		<nonDerivativeTransaction>
			<securityTitle>
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			<transactionDate>
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			<transactionCoding>
				<transactionFormType>4</transactionFormType>
				<transactionCode>S</transactionCode>
				<equitySwapInvolved>0</equitySwapInvolved>
			</transactionCoding>
			<transactionAmounts>
				<transactionShares>
					<value>3000</value>
				</transactionShares>
				<transactionPricePerShare>
					<value>5.92</value>
				</transactionPricePerShare>
				<transactionAcquiredDisposedCode>
					<value>D</value>
				</transactionAcquiredDisposedCode>
			</transactionAmounts>
			<postTransactionAmounts>
				<sharesOwnedFollowingTransaction>
					<value>9200.00</value>
				</sharesOwnedFollowingTransaction>
			</postTransactionAmounts>
			<ownershipNature>
				<directOrIndirectOwnership>
					<value>D</value>
				</directOrIndirectOwnership>
				<natureOfOwnership>
					<value/>
				</natureOfOwnership>
			</ownershipNature>
		</nonDerivativeTransaction>
		<nonDerivativeTransaction>
			<securityTitle>
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			</securityTitle>
			<transactionDate>
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			<transactionCoding>
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				<equitySwapInvolved>0</equitySwapInvolved>
			</transactionCoding>
			<transactionAmounts>
				<transactionShares>
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				</transactionShares>
				<transactionPricePerShare>
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				</transactionPricePerShare>
				<transactionAcquiredDisposedCode>
					<value>D</value>
				</transactionAcquiredDisposedCode>
			</transactionAmounts>
			<postTransactionAmounts>
				<sharesOwnedFollowingTransaction>
					<value>8000.00</value>
				</sharesOwnedFollowingTransaction>
			</postTransactionAmounts>
			<ownershipNature>
				<directOrIndirectOwnership>
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					<value/>
				</natureOfOwnership>
			</ownershipNature>
		</nonDerivativeTransaction>
		<nonDerivativeTransaction>
			<securityTitle>
				<value>Common Stock</value>
			</securityTitle>
			<transactionDate>
				<value>2003-12-26</value>
			</transactionDate>
			<deemedExecutionDate>
			</deemedExecutionDate>
			<transactionCoding>
				<transactionFormType>4</transactionFormType>
				<transactionCode>S</transactionCode>
				<equitySwapInvolved>0</equitySwapInvolved>
			</transactionCoding>
			<transactionAmounts>
				<transactionShares>
					<value>6300</value>
				</transactionShares>
				<transactionPricePerShare>
					<value>5.90</value>
				</transactionPricePerShare>
				<transactionAcquiredDisposedCode>
					<value>D</value>
				</transactionAcquiredDisposedCode>
			</transactionAmounts>
			<postTransactionAmounts>
				<sharesOwnedFollowingTransaction>
					<value>1700.00</value>
				</sharesOwnedFollowingTransaction>
			</postTransactionAmounts>
			<ownershipNature>
				<directOrIndirectOwnership>
					<value>D</value>
				</directOrIndirectOwnership>
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					<value/>
				</natureOfOwnership>
			</ownershipNature>
		</nonDerivativeTransaction>
		<nonDerivativeTransaction>
			<securityTitle>
				<value>Common Stock</value>
			</securityTitle>
			<transactionDate>
				<value>2003-12-26</value>
			</transactionDate>
			<deemedExecutionDate>
			</deemedExecutionDate>
			<transactionCoding>
				<transactionFormType>4</transactionFormType>
				<transactionCode>S</transactionCode>
				<equitySwapInvolved>0</equitySwapInvolved>
			</transactionCoding>
			<transactionAmounts>
				<transactionShares>
					<value>700</value>
				</transactionShares>
				<transactionPricePerShare>
					<value>5.91</value>
				</transactionPricePerShare>
				<transactionAcquiredDisposedCode>
					<value>D</value>
				</transactionAcquiredDisposedCode>
			</transactionAmounts>
			<postTransactionAmounts>
				<sharesOwnedFollowingTransaction>
					<value>1000.00</value>
				</sharesOwnedFollowingTransaction>
			</postTransactionAmounts>
			<ownershipNature>
				<directOrIndirectOwnership>
					<value>D</value>
				</directOrIndirectOwnership>
				<natureOfOwnership>
					<value/>
				</natureOfOwnership>
			</ownershipNature>
		</nonDerivativeTransaction>
	</nonDerivativeTable>
	<derivativeTable>
		<derivativeTransaction>
			<securityTitle>
				<value>Employee Stock Option (right to buy)</value>
			</securityTitle>
			<conversionOrExercisePrice>
				<value>2.50</value>
			</conversionOrExercisePrice>
			<transactionDate>
				<value>2003-12-24</value>
			</transactionDate>
			<deemedExecutionDate>
			</deemedExecutionDate>
			<transactionCoding>
				<transactionFormType>4</transactionFormType>
				<transactionCode>M</transactionCode>
				<equitySwapInvolved>0</equitySwapInvolved>
			</transactionCoding>
			<transactionAmounts>
				<transactionShares>
					<value>20000</value>
				</transactionShares>
				<transactionPricePerShare>
					<value>0</value>
				</transactionPricePerShare>
				<transactionAcquiredDisposedCode>
					<value>D</value>
				</transactionAcquiredDisposedCode>
			</transactionAmounts>
			<exerciseDate>
				<footnoteId id="F1"/>
			</exerciseDate>
			<expirationDate>
				<value>2010-01-19</value>
			</expirationDate>
			<underlyingSecurity>
				<underlyingSecurityTitle>
					<value>Common Stock</value>
				</underlyingSecurityTitle>
				<underlyingSecurityShares>
					<value>20000.00</value>
				</underlyingSecurityShares>
			</underlyingSecurity>
			<postTransactionAmounts>
				<sharesOwnedFollowingTransaction>
					<value>235000.00</value>
				</sharesOwnedFollowingTransaction>
			</postTransactionAmounts>
			<ownershipNature>
				<directOrIndirectOwnership>
					<value>D</value>
				</directOrIndirectOwnership>
				<natureOfOwnership>
					<value/>
				</natureOfOwnership>
			</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 employment (1/17/2001) and vests 1/48th per month for each month of service thereafter.</footnote>
	</footnotes>
	<remarks>
	</remarks>
	<ownerSignature>
		<signatureName>/s/ Piggott, James R.</signatureName>
		<signatureDate>2003-12-29</signatureDate>
	</ownerSignature>
</ownershipDocument>

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