-----BEGIN PRIVACY-ENHANCED MESSAGE-----
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,
 LtJCUoCuQXysPw3Gore48/HUgelT/7Fgq4oktgz4SOl8LmoBxHrFIYZzBPleOe6L
 hmZvpJAjsKDKhPvaQs0PhQ==

<SEC-DOCUMENT>0001140361-10-009119.txt : 20100302
<SEC-HEADER>0001140361-10-009119.hdr.sgml : 20100302
<ACCEPTANCE-DATETIME>20100302111812
ACCESSION NUMBER:		0001140361-10-009119
CONFORMED SUBMISSION TYPE:	4
PUBLIC DOCUMENT COUNT:		1
CONFORMED PERIOD OF REPORT:	20100226
FILED AS OF DATE:		20100302
DATE AS OF CHANGE:		20100302

REPORTING-OWNER:	

	OWNER DATA:	
		COMPANY CONFORMED NAME:			POSTERNAK NOEL G
		CENTRAL INDEX KEY:			0001182942

	FILING VALUES:
		FORM TYPE:		4
		SEC ACT:		1934 Act
		SEC FILE NUMBER:	000-18059
		FILM NUMBER:		10647838

	MAIL ADDRESS:	
		STREET 1:		100 CHARLES RIVER PLZ
		CITY:			BOSTON
		STATE:			MA
		ZIP:			02414

ISSUER:		

	COMPANY DATA:	
		COMPANY CONFORMED NAME:			PARAMETRIC TECHNOLOGY CORP
		CENTRAL INDEX KEY:			0000857005
		STANDARD INDUSTRIAL CLASSIFICATION:	SERVICES-PREPACKAGED SOFTWARE [7372]
		IRS NUMBER:				042866152
		STATE OF INCORPORATION:			MA
		FISCAL YEAR END:			0930

	BUSINESS ADDRESS:	
		STREET 1:		140 KENDRICK STREET
		CITY:			NEEDHAM
		STATE:			MA
		ZIP:			02494
		BUSINESS PHONE:		7813705000

	MAIL ADDRESS:	
		STREET 1:		140 KENDRICK STREET
		CITY:			NEEDHAM
		STATE:			MA
		ZIP:			02494
</SEC-HEADER>
<DOCUMENT>
<TYPE>4
<SEQUENCE>1
<FILENAME>doc1.xml
<DESCRIPTION>FORM 4
<TEXT>
<XML>
<?xml version="1.0"?>
<ownershipDocument>

    <schemaVersion>X0303</schemaVersion>

    <documentType>4</documentType>

    <periodOfReport>2010-02-26</periodOfReport>

    <notSubjectToSection16>0</notSubjectToSection16>

    <issuer>
        <issuerCik>0000857005</issuerCik>
        <issuerName>PARAMETRIC TECHNOLOGY CORP</issuerName>
        <issuerTradingSymbol>PMTC</issuerTradingSymbol>
    </issuer>

    <reportingOwner>
        <reportingOwnerId>
            <rptOwnerCik>0001182942</rptOwnerCik>
            <rptOwnerName>POSTERNAK NOEL G</rptOwnerName>
        </reportingOwnerId>
        <reportingOwnerAddress>
            <rptOwnerStreet1>POSTERNAK, BLANKSTEIN &amp; LUND</rptOwnerStreet1>
            <rptOwnerStreet2>800 BOYLSTON STREET, 32ND FLOOR</rptOwnerStreet2>
            <rptOwnerCity>BOSTON</rptOwnerCity>
            <rptOwnerState>MA</rptOwnerState>
            <rptOwnerZipCode>02119</rptOwnerZipCode>
            <rptOwnerStateDescription></rptOwnerStateDescription>
        </reportingOwnerAddress>
        <reportingOwnerRelationship>
            <isDirector>1</isDirector>
            <isOfficer>0</isOfficer>
            <isTenPercentOwner>0</isTenPercentOwner>
            <isOther>0</isOther>
            <officerTitle></officerTitle>
            <otherText></otherText>
        </reportingOwnerRelationship>
    </reportingOwner>

    <nonDerivativeTable>
        <nonDerivativeTransaction>
            <securityTitle>
                <value>Common Stock</value>
            </securityTitle>
            <transactionDate>
                <value>2010-02-26</value>
            </transactionDate>
            <deemedExecutionDate></deemedExecutionDate>
            <transactionCoding>
                <transactionFormType>4</transactionFormType>
                <transactionCode>S</transactionCode>
                <equitySwapInvolved>0</equitySwapInvolved>
            </transactionCoding>
            <transactionAmounts>
                <transactionShares>
                    <value>24000</value>
                </transactionShares>
                <transactionPricePerShare>
                    <value>17.3921</value>
                    <footnoteId id="F1"/>
                </transactionPricePerShare>
                <transactionAcquiredDisposedCode>
                    <value>D</value>
                </transactionAcquiredDisposedCode>
            </transactionAmounts>
            <postTransactionAmounts>
                <sharesOwnedFollowingTransaction>
                    <value>143671</value>
                </sharesOwnedFollowingTransaction>
            </postTransactionAmounts>
            <ownershipNature>
                <directOrIndirectOwnership>
                    <value>D</value>
                </directOrIndirectOwnership>
            </ownershipNature>
        </nonDerivativeTransaction>
    </nonDerivativeTable>

    <derivativeTable></derivativeTable>

    <footnotes>
        <footnote id="F1">This transaction was executed in multiple trades at prices ranging from $17.38 to $17.418.  The price reported above reflects the weighted average sale price.  The reporting person hereby undertakes to provide upon request to the SEC staff, the issuer or a security holder of the issuer full information regarding the number of shares and prices at which the transaction was effected.</footnote>
    </footnotes>

    <remarks></remarks>

    <ownerSignature>
        <signatureName>Catherine Gorecki by power of attorney filed 3/6/2008</signatureName>
        <signatureDate>2010-03-02</signatureDate>
    </ownerSignature>
</ownershipDocument>
</XML>
</TEXT>
</DOCUMENT>
</SEC-DOCUMENT>
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