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

    <schemaVersion>X0304</schemaVersion>

    <documentType>4</documentType>

    <periodOfReport>2011-09-07</periodOfReport>

    <notSubjectToSection16>0</notSubjectToSection16>

    <issuer>
        <issuerCik>0001030896</issuerCik>
        <issuerName>BLUEFLY INC</issuerName>
        <issuerTradingSymbol>BFLY</issuerTradingSymbol>
    </issuer>

    <reportingOwner>
        <reportingOwnerId>
            <rptOwnerCik>0000922382</rptOwnerCik>
            <rptOwnerName>QUANTUM INDUSTRIAL PARTNERS LDC ET AL</rptOwnerName>
        </reportingOwnerId>
        <reportingOwnerAddress>
            <rptOwnerStreet1>KAYA FLAMBOYAN 9,</rptOwnerStreet1>
            <rptOwnerStreet2></rptOwnerStreet2>
            <rptOwnerCity>WILLEMSTAD, CURACAO</rptOwnerCity>
            <rptOwnerState>P8</rptOwnerState>
            <rptOwnerZipCode>00000</rptOwnerZipCode>
            <rptOwnerStateDescription>NETHERLANDS ANTILLES</rptOwnerStateDescription>
        </reportingOwnerAddress>
        <reportingOwnerRelationship>
            <isDirector>0</isDirector>
            <isOfficer>0</isOfficer>
            <isTenPercentOwner>1</isTenPercentOwner>
            <isOther>0</isOther>
            <officerTitle></officerTitle>
            <otherText></otherText>
        </reportingOwnerRelationship>
    </reportingOwner>

    <reportingOwner>
        <reportingOwnerId>
            <rptOwnerCik>0001237660</rptOwnerCik>
            <rptOwnerName>QIH MANAGEMENT INVESTOR LP</rptOwnerName>
        </reportingOwnerId>
        <reportingOwnerAddress>
            <rptOwnerStreet1>888 SEVENTH AVENUE,</rptOwnerStreet1>
            <rptOwnerStreet2>33RD FLOOR</rptOwnerStreet2>
            <rptOwnerCity>NEW YORK</rptOwnerCity>
            <rptOwnerState>NY</rptOwnerState>
            <rptOwnerZipCode>10106</rptOwnerZipCode>
            <rptOwnerStateDescription></rptOwnerStateDescription>
        </reportingOwnerAddress>
        <reportingOwnerRelationship>
            <isDirector>0</isDirector>
            <isOfficer>0</isOfficer>
            <isTenPercentOwner>1</isTenPercentOwner>
            <isOther>0</isOther>
            <officerTitle></officerTitle>
            <otherText></otherText>
        </reportingOwnerRelationship>
    </reportingOwner>

    <reportingOwner>
        <reportingOwnerId>
            <rptOwnerCik>0001237658</rptOwnerCik>
            <rptOwnerName>QIH MANAGEMENT LLC</rptOwnerName>
        </reportingOwnerId>
        <reportingOwnerAddress>
            <rptOwnerStreet1>888 SEVENTH AVENUE,</rptOwnerStreet1>
            <rptOwnerStreet2>33RD FLOOR</rptOwnerStreet2>
            <rptOwnerCity>NEW YORK</rptOwnerCity>
            <rptOwnerState>NY</rptOwnerState>
            <rptOwnerZipCode>10106</rptOwnerZipCode>
            <rptOwnerStateDescription></rptOwnerStateDescription>
        </reportingOwnerAddress>
        <reportingOwnerRelationship>
            <isDirector>0</isDirector>
            <isOfficer>0</isOfficer>
            <isTenPercentOwner>1</isTenPercentOwner>
            <isOther>0</isOther>
            <officerTitle></officerTitle>
            <otherText></otherText>
        </reportingOwnerRelationship>
    </reportingOwner>

    <reportingOwner>
        <reportingOwnerId>
            <rptOwnerCik>0001029160</rptOwnerCik>
            <rptOwnerName>SOROS FUND MANAGEMENT LLC</rptOwnerName>
        </reportingOwnerId>
        <reportingOwnerAddress>
            <rptOwnerStreet1>888 SEVENTH AVENUE</rptOwnerStreet1>
            <rptOwnerStreet2>33RD FLOOR</rptOwnerStreet2>
            <rptOwnerCity>NEW YORK</rptOwnerCity>
            <rptOwnerState>NY</rptOwnerState>
            <rptOwnerZipCode>10106</rptOwnerZipCode>
            <rptOwnerStateDescription></rptOwnerStateDescription>
        </reportingOwnerAddress>
        <reportingOwnerRelationship>
            <isDirector>0</isDirector>
            <isOfficer>0</isOfficer>
            <isTenPercentOwner>1</isTenPercentOwner>
            <isOther>0</isOther>
            <officerTitle></officerTitle>
            <otherText></otherText>
        </reportingOwnerRelationship>
    </reportingOwner>

    <nonDerivativeTable>
        <nonDerivativeTransaction>
            <securityTitle>
                <value>Common Stock</value>
            </securityTitle>
            <transactionDate>
                <value>2011-09-07</value>
            </transactionDate>
            <deemedExecutionDate></deemedExecutionDate>
            <transactionCoding>
                <transactionFormType>4</transactionFormType>
                <transactionCode>P</transactionCode>
                <equitySwapInvolved>0</equitySwapInvolved>
            </transactionCoding>
            <transactionAmounts>
                <transactionShares>
                    <value>555555</value>
                </transactionShares>
                <transactionPricePerShare>
                    <value>1.80</value>
                </transactionPricePerShare>
                <transactionAcquiredDisposedCode>
                    <value>A</value>
                </transactionAcquiredDisposedCode>
            </transactionAmounts>
            <postTransactionAmounts>
                <sharesOwnedFollowingTransaction>
                    <value>6480070</value>
                </sharesOwnedFollowingTransaction>
            </postTransactionAmounts>
            <ownershipNature>
                <directOrIndirectOwnership>
                    <value>D</value>
                    <footnoteId id="F1"/>
                </directOrIndirectOwnership>
            </ownershipNature>
        </nonDerivativeTransaction>
    </nonDerivativeTable>

    <derivativeTable></derivativeTable>

    <footnotes>
        <footnote id="F1">These securities are held for the benefit of Quantum Industrial Partners LDC, an exempted limited duration company formed under the laws of the Cayman Islands (&quot;QIP&quot;).  QIH Management Investor, L.P., an investment advisory firm organized as a Delaware limited partnership (&quot;QIHMI&quot;), is a minority shareholder of, and is vested with investment discretion with respect to portfolio assets held for the account of, QIP.  The sole general partner of QIHMI is QIH Management LLC, a Delaware limited liability company (&quot;QIH Management&quot;).  Soros Fund Management LLC, a Delaware limited liability company, is the sole managing member of QIH Management.</footnote>
    </footnotes>

    <remarks>The filing of this statement shall not be deemed an admission that any of the Reporting Persons are the beneficial owner of any securities not held directly for its account for purposes of Section 16 of the Securities Act of 1934, as amended, or otherwise.</remarks>

    <ownerSignature>
        <signatureName>/s/ Jay Schoenfarber, as Attorney-in-Fact of Quantum Industrial Partners LDC et al</signatureName>
        <signatureDate>2011-09-09</signatureDate>
    </ownerSignature>

    <ownerSignature>
        <signatureName>/s/ Jay Schoenfarber, as Assistant General Counsel of Soros Fund Management, LLC, which is the Managing Member of QIH Management LLC</signatureName>
        <signatureDate>2011-09-09</signatureDate>
    </ownerSignature>

    <ownerSignature>
        <signatureName>/s/ Jay Schoenfarber, as Assistant General Counsel of Soros Fund Management LLC</signatureName>
        <signatureDate>2011-09-09</signatureDate>
    </ownerSignature>

    <ownerSignature>
        <signatureName>/s/ Jay Schoenfarber, as Assistant General Counsel of Soros Fund Management, LLC, which is the Managing Member of QIH Management LLC, which is the general partner of QIH Management Investor, L.P.</signatureName>
        <signatureDate>2011-09-09</signatureDate>
    </ownerSignature>
</ownershipDocument>
