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Proc-Type: 2001,MIC-CLEAR
Originator-Name: webmaster@www.sec.gov
Originator-Key-Asymmetric:
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 TWSM7vrzLADbmYQaionwg5sDW3P6oaM5D3tdezXMm7z1T+B+twIDAQAB
MIC-Info: RSA-MD5,RSA,
 MCiHdYSOiEGr5lbxOUdNOMfHxSl+9jsEOzkp98uhs+ySRDFFBuZ0tMY/jwDUIr3t
 n3EDTS2nDFaFlM8lqux5XQ==

<SEC-DOCUMENT>0000893877-09-000529.txt : 20091112
<SEC-HEADER>0000893877-09-000529.hdr.sgml : 20091111
<ACCEPTANCE-DATETIME>20091112194106
ACCESSION NUMBER:		0000893877-09-000529
CONFORMED SUBMISSION TYPE:	4
PUBLIC DOCUMENT COUNT:		1
CONFORMED PERIOD OF REPORT:	20091111
FILED AS OF DATE:		20091112
DATE AS OF CHANGE:		20091112

REPORTING-OWNER:	

	OWNER DATA:	
		COMPANY CONFORMED NAME:			Snowden Joseph I
		CENTRAL INDEX KEY:			0001380005

	FILING VALUES:
		FORM TYPE:		4
		SEC ACT:		1934 Act
		SEC FILE NUMBER:	001-10348
		FILM NUMBER:		091178745

	MAIL ADDRESS:	
		STREET 1:		4650 SW MACADAM
		STREET 2:		SUITE 440
		CITY:			PORTLAND
		STATE:			OR
		ZIP:			97239

ISSUER:		

	COMPANY DATA:	
		COMPANY CONFORMED NAME:			PRECISION CASTPARTS CORP
		CENTRAL INDEX KEY:			0000079958
		STANDARD INDUSTRIAL CLASSIFICATION:	IRON & STEEL FOUNDRIES [3320]
		IRS NUMBER:				930460598
		STATE OF INCORPORATION:			OR
		FISCAL YEAR END:			0329

	BUSINESS ADDRESS:	
		STREET 1:		4650 SW MACADAM AVE
		STREET 2:		STE 440
		CITY:			PORTLAND
		STATE:			OR
		ZIP:			97239
		BUSINESS PHONE:		503.417.4800

	MAIL ADDRESS:	
		STREET 1:		4650 SW MACADAM AVE
		STREET 2:		STE 440
		CITY:			PORTLAND
		STATE:			OR
		ZIP:			97239
</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>2009-11-11</periodOfReport>

    <issuer>
        <issuerCik>0000079958</issuerCik>
        <issuerName>PRECISION CASTPARTS CORP</issuerName>
        <issuerTradingSymbol>PCP</issuerTradingSymbol>
    </issuer>

    <reportingOwner>
        <reportingOwnerId>
            <rptOwnerCik>0001380005</rptOwnerCik>
            <rptOwnerName>Snowden Joseph I</rptOwnerName>
        </reportingOwnerId>
        <reportingOwnerAddress>
            <rptOwnerStreet1>PRECISION CASTPARTS CORP.</rptOwnerStreet1>
            <rptOwnerStreet2>4650 SW MACADAM AVENUE, SUITE 400</rptOwnerStreet2>
            <rptOwnerCity>PORTLAND</rptOwnerCity>
            <rptOwnerState>OR</rptOwnerState>
            <rptOwnerZipCode>97239</rptOwnerZipCode>
            <rptOwnerStateDescription></rptOwnerStateDescription>
        </reportingOwnerAddress>
        <reportingOwnerRelationship>
            <isDirector>0</isDirector>
            <isOfficer>1</isOfficer>
            <isTenPercentOwner>0</isTenPercentOwner>
            <isOther>0</isOther>
            <officerTitle>Sr. VP, Pres. Special Metals</officerTitle>
        </reportingOwnerRelationship>
    </reportingOwner>

    <derivativeTable>
        <derivativeTransaction>
            <securityTitle>
                <value>Non-Qualified Stock Option (right to buy)</value>
            </securityTitle>
            <conversionOrExercisePrice>
                <value>101.41</value>
            </conversionOrExercisePrice>
            <transactionDate>
                <value>2009-11-11</value>
            </transactionDate>
            <transactionCoding>
                <transactionFormType>4</transactionFormType>
                <transactionCode>A</transactionCode>
                <equitySwapInvolved>0</equitySwapInvolved>
            </transactionCoding>
            <transactionAmounts>
                <transactionShares>
                    <value>27600</value>
                </transactionShares>
                <transactionPricePerShare>
                    <value>0</value>
                </transactionPricePerShare>
                <transactionAcquiredDisposedCode>
                    <value>A</value>
                </transactionAcquiredDisposedCode>
            </transactionAmounts>
            <exerciseDate>
                <footnoteId id="F1"/>
            </exerciseDate>
            <expirationDate>
                <value>2019-11-11</value>
            </expirationDate>
            <underlyingSecurity>
                <underlyingSecurityTitle>
                    <value>Common Stock</value>
                </underlyingSecurityTitle>
                <underlyingSecurityShares>
                    <value>27600</value>
                </underlyingSecurityShares>
            </underlyingSecurity>
            <postTransactionAmounts>
                <sharesOwnedFollowingTransaction>
                    <value>27600</value>
                </sharesOwnedFollowingTransaction>
            </postTransactionAmounts>
            <ownershipNature>
                <directOrIndirectOwnership>
                    <value>D</value>
                </directOrIndirectOwnership>
                <natureOfOwnership>
                    <value></value>
                </natureOfOwnership>
            </ownershipNature>
        </derivativeTransaction>
    </derivativeTable>

    <footnotes>
        <footnote id="F1">The option was granted on November 11, 2009 and vests in four equal annual installments on each of the first four anniversaries of the grant date.</footnote>
    </footnotes>

    <remarks></remarks>

    <ownerSignature>
        <signatureName>Jason A. Dalton, Attorney-in-Fact</signatureName>
        <signatureDate>2009-11-12</signatureDate>
    </ownerSignature>
</ownershipDocument>
</XML>
</TEXT>
</DOCUMENT>
</SEC-DOCUMENT>
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