-----BEGIN PRIVACY-ENHANCED MESSAGE-----
Proc-Type: 2001,MIC-CLEAR
Originator-Name: webmaster@www.sec.gov
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MIC-Info: RSA-MD5,RSA,
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 kNNrvf6CwmneaZCkv0GdsQ==

<SEC-DOCUMENT>0000884905-09-000003.txt : 20090129
<SEC-HEADER>0000884905-09-000003.hdr.sgml : 20090129
<ACCEPTANCE-DATETIME>20090129151354
ACCESSION NUMBER:		0000884905-09-000003
CONFORMED SUBMISSION TYPE:	4
PUBLIC DOCUMENT COUNT:		1
CONFORMED PERIOD OF REPORT:	20090127
FILED AS OF DATE:		20090129
DATE AS OF CHANGE:		20090129

REPORTING-OWNER:	

	OWNER DATA:	
		COMPANY CONFORMED NAME:			HALL IRA D
		CENTRAL INDEX KEY:			0001202248

	FILING VALUES:
		FORM TYPE:		4
		SEC ACT:		1934 Act
		SEC FILE NUMBER:	001-11037
		FILM NUMBER:		09554320

	BUSINESS ADDRESS:	
		BUSINESS PHONE:		8132281431

	MAIL ADDRESS:	
		STREET 1:		C/O TECO ENERGY INC
		STREET 2:		P O BOX 111
		CITY:			TAMPA
		STATE:			FL
		ZIP:			336010111

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

    <schemaVersion>X0303</schemaVersion>

    <documentType>4</documentType>

    <periodOfReport>2009-01-27</periodOfReport>

    <notSubjectToSection16>0</notSubjectToSection16>

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

    <reportingOwner>
        <reportingOwnerId>
            <rptOwnerCik>0001202248</rptOwnerCik>
            <rptOwnerName>HALL IRA D</rptOwnerName>
        </reportingOwnerId>
        <reportingOwnerAddress>
            <rptOwnerStreet1>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>

    <derivativeTable>
        <derivativeTransaction>
            <securityTitle>
                <value>Deferred Stock</value>
            </securityTitle>
            <conversionOrExercisePrice>
                <value>0</value>
                <footnoteId id="F1"/>
            </conversionOrExercisePrice>
            <transactionDate>
                <value>2009-01-27</value>
            </transactionDate>
            <transactionCoding>
                <transactionFormType>4</transactionFormType>
                <transactionCode>A</transactionCode>
                <equitySwapInvolved>0</equitySwapInvolved>
            </transactionCoding>
            <transactionTimeliness>
                <value></value>
            </transactionTimeliness>
            <transactionAmounts>
                <transactionShares>
                    <value>349.561</value>
                </transactionShares>
                <transactionPricePerShare>
                    <value>0</value>
                </transactionPricePerShare>
                <transactionAcquiredDisposedCode>
                    <value>A</value>
                </transactionAcquiredDisposedCode>
            </transactionAmounts>
            <exerciseDate>
                <footnoteId id="F2"/>
            </exerciseDate>
            <expirationDate>
                <footnoteId id="F2"/>
            </expirationDate>
            <underlyingSecurity>
                <underlyingSecurityTitle>
                    <value>Common Stock</value>
                </underlyingSecurityTitle>
                <underlyingSecurityShares>
                    <value>349.561</value>
                </underlyingSecurityShares>
            </underlyingSecurity>
            <postTransactionAmounts>
                <sharesOwnedFollowingTransaction>
                    <value>2091.828</value>
                    <footnoteId id="F3"/>
                </sharesOwnedFollowingTransaction>
            </postTransactionAmounts>
            <ownershipNature>
                <directOrIndirectOwnership>
                    <value>D</value>
                </directOrIndirectOwnership>
            </ownershipNature>
        </derivativeTransaction>
    </derivativeTable>

    <footnotes>
        <footnote id="F1">Conversion to Praxair Common Stock is on a 1-for-1 basis.</footnote>
        <footnote id="F2">Deferred stock units acquired by reporting person under the Praxair, Inc. Director's Fees Deferral Plan (the &quot;Plan&quot;) and are to be settled in Praxair Common Stock upon the reporting person's retirement or termination of service.</footnote>
        <footnote id="F3">This total includes shares previously acquired through automatic dividend reinvestment under the Plan.</footnote>
    </footnotes>

    <ownerSignature>
        <signatureName>Anthony M. Pepper, Attorney-in-Fact</signatureName>
        <signatureDate>2009-01-29</signatureDate>
    </ownerSignature>
</ownershipDocument>
</XML>
</TEXT>
</DOCUMENT>
</SEC-DOCUMENT>
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