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

    <schemaVersion>X0206</schemaVersion>

    <documentType>3</documentType>

    <periodOfReport>2022-05-09</periodOfReport>

    <noSecuritiesOwned>0</noSecuritiesOwned>

    <issuer>
        <issuerCik>0001050377</issuerCik>
        <issuerName>PC CONNECTION INC</issuerName>
        <issuerTradingSymbol>CNXN</issuerTradingSymbol>
    </issuer>

    <reportingOwner>
        <reportingOwnerId>
            <rptOwnerCik>0001926570</rptOwnerCik>
            <rptOwnerName>Comack Trust</rptOwnerName>
        </reportingOwnerId>
        <reportingOwnerAddress>
            <rptOwnerStreet1>450 MARLBORO STREET</rptOwnerStreet1>
            <rptOwnerStreet2></rptOwnerStreet2>
            <rptOwnerCity>KEENE</rptOwnerCity>
            <rptOwnerState>NH</rptOwnerState>
            <rptOwnerZipCode>03431</rptOwnerZipCode>
            <rptOwnerStateDescription></rptOwnerStateDescription>
        </reportingOwnerAddress>
        <reportingOwnerRelationship>
            <isDirector>false</isDirector>
            <isOfficer>false</isOfficer>
            <isTenPercentOwner>true</isTenPercentOwner>
            <isOther>false</isOther>
            <officerTitle></officerTitle>
            <otherText></otherText>
        </reportingOwnerRelationship>
    </reportingOwner>

    <nonDerivativeTable>
        <nonDerivativeHolding>
            <securityTitle>
                <value>Common Stock</value>
            </securityTitle>
            <postTransactionAmounts>
                <sharesOwnedFollowingTransaction>
                    <value>5000000.00</value>
                </sharesOwnedFollowingTransaction>
            </postTransactionAmounts>
            <ownershipNature>
                <directOrIndirectOwnership>
                    <value>D</value>
                    <footnoteId id="F1"/>
                </directOrIndirectOwnership>
            </ownershipNature>
        </nonDerivativeHolding>
    </nonDerivativeTable>

    <derivativeTable></derivativeTable>

    <footnotes>
        <footnote id="F1">On May 9, 2022, Patricia Gallup funded the Comack Trust, a grantor retained annuity trust formed under the laws of the State of New Hampshire, with 5,000,000 shares of common stock. Patricia Gallup is the sole trustee and sole annuitant of the Comack Trust.</footnote>
    </footnotes>

    <remarks></remarks>

    <ownerSignature>
        <signatureName>Patricia Gallup, As Trustee</signatureName>
        <signatureDate>2022-05-17</signatureDate>
    </ownerSignature>
</ownershipDocument>
