<?xml version="1.0"?>
<ownershipDocument>

    <schemaVersion>X0202</schemaVersion>

    <documentType>4</documentType>

    <periodOfReport>2004-08-24</periodOfReport>

    <notSubjectToSection16>0</notSubjectToSection16>

    <issuer>
        <issuerCik>0000724988</issuerCik>
        <issuerName>PARLEX CORP</issuerName>
        <issuerTradingSymbol>PRLX</issuerTradingSymbol>
    </issuer>

    <reportingOwner>
        <reportingOwnerId>
            <rptOwnerCik>0001254006</rptOwnerCik>
            <rptOwnerName>MURPHY PETER J</rptOwnerName>
        </reportingOwnerId>
        <reportingOwnerAddress>
            <rptOwnerStreet1>ONE PARLEX PLACE</rptOwnerStreet1>
            <rptOwnerStreet2></rptOwnerStreet2>
            <rptOwnerCity>METHUEN</rptOwnerCity>
            <rptOwnerState>MA</rptOwnerState>
            <rptOwnerZipCode>01844-</rptOwnerZipCode>
            <rptOwnerStateDescription></rptOwnerStateDescription>
        </reportingOwnerAddress>
        <reportingOwnerRelationship>
            <isDirector>1</isDirector>
            <isOfficer>1</isOfficer>
            <isTenPercentOwner>0</isTenPercentOwner>
            <isOther>0</isOther>
            <officerTitle>President and CEO</officerTitle>
            <otherText></otherText>
        </reportingOwnerRelationship>
    </reportingOwner>

    <nonDerivativeTable></nonDerivativeTable>

    <derivativeTable>
        <derivativeTransaction>
            <securityTitle>
                <value>Stock Options (Right to buy)</value>
            </securityTitle>
            <conversionOrExercisePrice>
                <value>6.11</value>
            </conversionOrExercisePrice>
            <transactionDate>
                <value>2004-08-24</value>
            </transactionDate>
            <deemedExecutionDate>
                <value>2004-08-24</value>
            </deemedExecutionDate>
            <transactionCoding>
                <transactionFormType>4</transactionFormType>
                <transactionCode>A</transactionCode>
                <equitySwapInvolved>0</equitySwapInvolved>
            </transactionCoding>
            <transactionAmounts>
                <transactionShares>
                    <value>25000</value>
                </transactionShares>
                <transactionPricePerShare>
                    <value>6.11</value>
                </transactionPricePerShare>
                <transactionAcquiredDisposedCode>
                    <value>A</value>
                </transactionAcquiredDisposedCode>
            </transactionAmounts>
            <exerciseDate>
                <value>2005-08-24</value>
                <footnoteId id="F1"/>
            </exerciseDate>
            <expirationDate>
                <value>2014-08-24</value>
            </expirationDate>
            <underlyingSecurity>
                <underlyingSecurityTitle>
                    <value>Common Stock</value>
                </underlyingSecurityTitle>
                <underlyingSecurityShares>
                    <value>25000</value>
                </underlyingSecurityShares>
            </underlyingSecurity>
            <postTransactionAmounts>
                <sharesOwnedFollowingTransaction>
                    <value>25000</value>
                </sharesOwnedFollowingTransaction>
            </postTransactionAmounts>
            <ownershipNature>
                <directOrIndirectOwnership>
                    <value>D</value>
                </directOrIndirectOwnership>
            </ownershipNature>
        </derivativeTransaction>
    </derivativeTable>

    <footnotes>
        <footnote id="F1">Stock option grant under the 2001 Employees' Stock Option Plan.  Exercisable in four equal installments, beginning one year from date of grant.</footnote>
    </footnotes>

    <ownerSignature>
        <signatureName>Annemarie Bell, as Attorney-in-Fact</signatureName>
        <signatureDate>2004-08-26</signatureDate>
    </ownerSignature>
</ownershipDocument>
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X0202
4
2004-08-24
0
0000724988
PARLEX CORP
PRLX
0001254006
MURPHY PETER J
ONE PARLEX PLACE
METHUEN
MA
01844-
1
1
0
0
President and CEO
Stock Options (Right to buy)
6.11
2004-08-24
2004-08-24
4
A
0
25000
6.11
A
2005-08-24
2014-08-24
Common Stock
25000
25000
D
Stock option grant under the 2001 Employees' Stock Option Plan.  Exercisable in four equal installments, beginning one year from date of grant.
Annemarie Bell, as Attorney-in-Fact
2004-08-26