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Proc-Type: 2001,MIC-CLEAR
Originator-Name: webmaster@www.sec.gov
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 TWSM7vrzLADbmYQaionwg5sDW3P6oaM5D3tdezXMm7z1T+B+twIDAQAB
MIC-Info: RSA-MD5,RSA,
 L1xoAseIGuAlDK+pG4avEaId9Vy5i7edIvHeUUBaOOgs+cUt90JiX0KZwUk9KAXq
 gD61jxJU2UAeVJlUL1ZArA==

<SEC-DOCUMENT>0000884905-08-000070.txt : 20080924
<SEC-HEADER>0000884905-08-000070.hdr.sgml : 20080924
<ACCEPTANCE-DATETIME>20080924110314
ACCESSION NUMBER:		0000884905-08-000070
CONFORMED SUBMISSION TYPE:	4
PUBLIC DOCUMENT COUNT:		1
CONFORMED PERIOD OF REPORT:	20080923
FILED AS OF DATE:		20080924
DATE AS OF CHANGE:		20080924

ISSUER:		

	COMPANY DATA:	
		COMPANY CONFORMED NAME:			PRAXAIR INC
		CENTRAL INDEX KEY:			0000884905
		STANDARD INDUSTRIAL CLASSIFICATION:	INDUSTRIAL INORGANIC CHEMICALS [2810]
		IRS NUMBER:				061249050
		STATE OF INCORPORATION:			DE
		FISCAL YEAR END:			1231

	BUSINESS ADDRESS:	
		STREET 1:		39 OLD RIDGEBURY RD
		CITY:			DANBURY
		STATE:			CT
		ZIP:			06810-5113
		BUSINESS PHONE:		2038372000

	MAIL ADDRESS:	
		STREET 1:		39 OLD RIDGEBURY ROAD
		CITY:			DANBURY
		STATE:			CT
		ZIP:			06810-5113

	FORMER COMPANY:	
		FORMER CONFORMED NAME:	UNION CARBIDE INDUSTRIAL GASES INC
		DATE OF NAME CHANGE:	19600201

REPORTING-OWNER:	

	OWNER DATA:	
		COMPANY CONFORMED NAME:			DICCIANI NANCE K
		CENTRAL INDEX KEY:			0001198097

	FILING VALUES:
		FORM TYPE:		4
		SEC ACT:		1934 Act
		SEC FILE NUMBER:	001-11037
		FILM NUMBER:		081085875

	BUSINESS ADDRESS:	
		BUSINESS PHONE:		9734555513

	MAIL ADDRESS:	
		STREET 1:		HONEYWELL
		STREET 2:		101 COLUMBIA ROAD
		CITY:			MORRISTOWN
		STATE:			NJ
		ZIP:			07962
</SEC-HEADER>
<DOCUMENT>
<TYPE>4
<SEQUENCE>1
<FILENAME>edgar.xml
<DESCRIPTION>PRIMARY DOCUMENT
<TEXT>
<XML>
<?xml version="1.0"?>
<ownershipDocument>

    <schemaVersion>X0303</schemaVersion>

    <documentType>4</documentType>

    <periodOfReport>2008-09-23</periodOfReport>

    <issuer>
        <issuerCik>0000884905</issuerCik>
        <issuerName>PRAXAIR INC</issuerName>
        <issuerTradingSymbol>PX</issuerTradingSymbol>
    </issuer>

    <reportingOwner>
        <reportingOwnerId>
            <rptOwnerCik>0001198097</rptOwnerCik>
            <rptOwnerName>DICCIANI NANCE K</rptOwnerName>
        </reportingOwnerId>
        <reportingOwnerAddress>
            <rptOwnerStreet1>C/O PRAXAIR, INC.</rptOwnerStreet1>
            <rptOwnerStreet2>39 OLD RIDGEBURY ROAD</rptOwnerStreet2>
            <rptOwnerCity>DANBURY</rptOwnerCity>
            <rptOwnerState>CT</rptOwnerState>
            <rptOwnerZipCode>06810-5113</rptOwnerZipCode>
            <rptOwnerStateDescription></rptOwnerStateDescription>
        </reportingOwnerAddress>
        <reportingOwnerRelationship>
            <isDirector>1</isDirector>
            <isOfficer>0</isOfficer>
            <isTenPercentOwner>0</isTenPercentOwner>
            <isOther>0</isOther>
        </reportingOwnerRelationship>
    </reportingOwner>

    <nonDerivativeTable>
        <nonDerivativeHolding>
            <securityTitle>
                <value>Common Stock</value>
            </securityTitle>
            <postTransactionAmounts>
                <sharesOwnedFollowingTransaction>
                    <value>750</value>
                </sharesOwnedFollowingTransaction>
            </postTransactionAmounts>
            <ownershipNature>
                <directOrIndirectOwnership>
                    <value>D</value>
                </directOrIndirectOwnership>
                <natureOfOwnership>
                    <value></value>
                </natureOfOwnership>
            </ownershipNature>
        </nonDerivativeHolding>
    </nonDerivativeTable>

    <derivativeTable>
        <derivativeTransaction>
            <securityTitle>
                <value>Stock Option (right to buy)</value>
            </securityTitle>
            <conversionOrExercisePrice>
                <value>80.01</value>
            </conversionOrExercisePrice>
            <transactionDate>
                <value>2008-09-23</value>
            </transactionDate>
            <transactionCoding>
                <transactionFormType>4</transactionFormType>
                <transactionCode>A</transactionCode>
                <equitySwapInvolved>0</equitySwapInvolved>
            </transactionCoding>
            <transactionAmounts>
                <transactionShares>
                    <value>1546</value>
                </transactionShares>
                <transactionPricePerShare>
                    <value>0</value>
                </transactionPricePerShare>
                <transactionAcquiredDisposedCode>
                    <value>A</value>
                </transactionAcquiredDisposedCode>
            </transactionAmounts>
            <exerciseDate>
                <value>2009-09-23</value>
                <footnoteId id="F1"/>
            </exerciseDate>
            <expirationDate>
                <value>2018-09-23</value>
            </expirationDate>
            <underlyingSecurity>
                <underlyingSecurityTitle>
                    <value>Common Stock</value>
                </underlyingSecurityTitle>
                <underlyingSecurityShares>
                    <value>1546</value>
                </underlyingSecurityShares>
            </underlyingSecurity>
            <postTransactionAmounts>
                <sharesOwnedFollowingTransaction>
                    <value>1546</value>
                </sharesOwnedFollowingTransaction>
            </postTransactionAmounts>
            <ownershipNature>
                <directOrIndirectOwnership>
                    <value>D</value>
                </directOrIndirectOwnership>
                <natureOfOwnership>
                    <value></value>
                </natureOfOwnership>
            </ownershipNature>
        </derivativeTransaction>
    </derivativeTable>

    <footnotes>
        <footnote id="F1">This option becomes exercisable in three (3) equal annual installments beginning on the first anniversary of the date of grant.</footnote>
    </footnotes>

    <remarks></remarks>

    <ownerSignature>
        <signatureName>Anthony M. Pepper, Attorney-In-Fact</signatureName>
        <signatureDate>2008-09-23</signatureDate>
    </ownerSignature>
</ownershipDocument>
</XML>
</TEXT>
</DOCUMENT>
</SEC-DOCUMENT>
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