-----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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<SEC-DOCUMENT>0001045309-08-000016.txt : 20081203
<SEC-HEADER>0001045309-08-000016.hdr.sgml : 20081203
<ACCEPTANCE-DATETIME>20081203164151
ACCESSION NUMBER:		0001045309-08-000016
CONFORMED SUBMISSION TYPE:	4
PUBLIC DOCUMENT COUNT:		1
CONFORMED PERIOD OF REPORT:	20081202
FILED AS OF DATE:		20081203
DATE AS OF CHANGE:		20081203

REPORTING-OWNER:	

	OWNER DATA:	
		COMPANY CONFORMED NAME:			Shelnitz Mark A
		CENTRAL INDEX KEY:			0001325901

	FILING VALUES:
		FORM TYPE:		4
		SEC ACT:		1934 Act
		SEC FILE NUMBER:	001-13953
		FILM NUMBER:		081227855

	BUSINESS ADDRESS:	
		BUSINESS PHONE:		410-531-4362

	MAIL ADDRESS:	
		STREET 1:		C/O W. R. GRACE & CO.
		STREET 2:		7500 GRACE DRIVE
		CITY:			COLUMBIA
		STATE:			MD
		ZIP:			21044

ISSUER:		

	COMPANY DATA:	
		COMPANY CONFORMED NAME:			W R GRACE & CO
		CENTRAL INDEX KEY:			0001045309
		STANDARD INDUSTRIAL CLASSIFICATION:	CHEMICALS & ALLIED PRODUCTS [2800]
		IRS NUMBER:				650773649
		STATE OF INCORPORATION:			DE
		FISCAL YEAR END:			1231

	BUSINESS ADDRESS:	
		STREET 1:		7500 GRACE DRIVE
		CITY:			COLUMBIA
		STATE:			MD
		ZIP:			21044
		BUSINESS PHONE:		410 531 4000

	MAIL ADDRESS:	
		STREET 1:		7500 GRACE DRIVE
		CITY:			COLUMBIA
		STATE:			MD
		ZIP:			21044

	FORMER COMPANY:	
		FORMER CONFORMED NAME:	GRACE SPECIALTY CHEMICALS INC
		DATE OF NAME CHANGE:	19970902
</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>2008-12-02</periodOfReport>

    <notSubjectToSection16>0</notSubjectToSection16>

    <issuer>
        <issuerCik>0001045309</issuerCik>
        <issuerName>W R GRACE &amp; CO</issuerName>
        <issuerTradingSymbol>GRA</issuerTradingSymbol>
    </issuer>

    <reportingOwner>
        <reportingOwnerId>
            <rptOwnerCik>0001325901</rptOwnerCik>
            <rptOwnerName>Shelnitz Mark A</rptOwnerName>
        </reportingOwnerId>
        <reportingOwnerAddress>
            <rptOwnerStreet1>C/O W. R. GRACE &amp; CO.</rptOwnerStreet1>
            <rptOwnerStreet2>7500 GRACE DRIVE</rptOwnerStreet2>
            <rptOwnerCity>COLUMBIA</rptOwnerCity>
            <rptOwnerState>MD</rptOwnerState>
            <rptOwnerZipCode>21044</rptOwnerZipCode>
            <rptOwnerStateDescription></rptOwnerStateDescription>
        </reportingOwnerAddress>
        <reportingOwnerRelationship>
            <isDirector>0</isDirector>
            <isOfficer>1</isOfficer>
            <isTenPercentOwner>0</isTenPercentOwner>
            <isOther>0</isOther>
            <officerTitle>VP, Gen. Counsel and Secretary</officerTitle>
        </reportingOwnerRelationship>
    </reportingOwner>

    <nonDerivativeTable>
        <nonDerivativeTransaction>
            <securityTitle>
                <value>Common Stock, par value $0.01 per share</value>
                <footnoteId id="F1"/>
            </securityTitle>
            <transactionDate>
                <value>2008-12-02</value>
            </transactionDate>
            <transactionCoding>
                <transactionFormType>4</transactionFormType>
                <transactionCode>P</transactionCode>
                <equitySwapInvolved>0</equitySwapInvolved>
            </transactionCoding>
            <transactionTimeliness>
                <value></value>
            </transactionTimeliness>
            <transactionAmounts>
                <transactionShares>
                    <value>50000</value>
                </transactionShares>
                <transactionPricePerShare>
                    <value>3.83</value>
                </transactionPricePerShare>
                <transactionAcquiredDisposedCode>
                    <value>A</value>
                </transactionAcquiredDisposedCode>
            </transactionAmounts>
            <postTransactionAmounts>
                <sharesOwnedFollowingTransaction>
                    <value>53500</value>
                </sharesOwnedFollowingTransaction>
            </postTransactionAmounts>
            <ownershipNature>
                <directOrIndirectOwnership>
                    <value>D</value>
                </directOrIndirectOwnership>
            </ownershipNature>
        </nonDerivativeTransaction>
        <nonDerivativeHolding>
            <securityTitle>
                <value>Common Stock, par value $0.01 per share</value>
                <footnoteId id="F1"/>
            </securityTitle>
            <postTransactionAmounts>
                <sharesOwnedFollowingTransaction>
                    <value>9420.8496</value>
                </sharesOwnedFollowingTransaction>
            </postTransactionAmounts>
            <ownershipNature>
                <directOrIndirectOwnership>
                    <value>I</value>
                </directOrIndirectOwnership>
                <natureOfOwnership>
                    <value>By Trust</value>
                    <footnoteId id="F2"/>
                </natureOfOwnership>
            </ownershipNature>
        </nonDerivativeHolding>
    </nonDerivativeTable>

    <footnotes>
        <footnote id="F1">Each share of Common stock also represents one Preferred Share Purchase Right.  Each such Right entitles the holder to purchase Preferred Stock or other securities or property upon the occurrence of certain events and subject to certain conditions.</footnote>
        <footnote id="F2">Such shares are held in a &quot;Rabbi&quot; trust established by the issuer for the benefit of certain officers and directors.</footnote>
    </footnotes>

    <ownerSignature>
        <signatureName>Michael W. Conron, Attorney-In-Fact</signatureName>
        <signatureDate>2008-12-03</signatureDate>
    </ownerSignature>
</ownershipDocument>
</XML>
</TEXT>
</DOCUMENT>
</SEC-DOCUMENT>
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