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

    <schemaVersion>X0306</schemaVersion>

    <documentType>4</documentType>

    <periodOfReport>2016-11-29</periodOfReport>

    <notSubjectToSection16>0</notSubjectToSection16>

    <issuer>
        <issuerCik>0000827809</issuerCik>
        <issuerName>QLT INC/BC</issuerName>
        <issuerTradingSymbol>NVLN</issuerTradingSymbol>
    </issuer>

    <reportingOwner>
        <reportingOwnerId>
            <rptOwnerCik>0001410289</rptOwnerCik>
            <rptOwnerName>Szela Mary T</rptOwnerName>
        </reportingOwnerId>
        <reportingOwnerAddress>
            <rptOwnerStreet1>C/O NOVELION THERAPEUTICS INC.</rptOwnerStreet1>
            <rptOwnerStreet2>997 GREAT NORTHERN WAY, SUITE 250</rptOwnerStreet2>
            <rptOwnerCity>VANCOUVER</rptOwnerCity>
            <rptOwnerState>A1</rptOwnerState>
            <rptOwnerZipCode>V5T 4T5</rptOwnerZipCode>
            <rptOwnerStateDescription>BRITISH COLUMBIA, CANADA</rptOwnerStateDescription>
        </reportingOwnerAddress>
        <reportingOwnerRelationship>
            <isDirector>1</isDirector>
            <isOfficer>1</isOfficer>
            <isTenPercentOwner>0</isTenPercentOwner>
            <isOther>0</isOther>
            <officerTitle>Chief Executive Officer</officerTitle>
        </reportingOwnerRelationship>
    </reportingOwner>

    <derivativeTable>
        <derivativeTransaction>
            <securityTitle>
                <value>Restricted Stock Units</value>
            </securityTitle>
            <conversionOrExercisePrice>
                <footnoteId id="F1"/>
            </conversionOrExercisePrice>
            <transactionDate>
                <value>2016-11-29</value>
            </transactionDate>
            <transactionCoding>
                <transactionFormType>4</transactionFormType>
                <transactionCode>A</transactionCode>
                <equitySwapInvolved>0</equitySwapInvolved>
            </transactionCoding>
            <transactionTimeliness>
                <value></value>
            </transactionTimeliness>
            <transactionAmounts>
                <transactionShares>
                    <value>99483</value>
                </transactionShares>
                <transactionPricePerShare>
                    <footnoteId id="F3"/>
                    <footnoteId id="F4"/>
                </transactionPricePerShare>
                <transactionAcquiredDisposedCode>
                    <value>A</value>
                </transactionAcquiredDisposedCode>
            </transactionAmounts>
            <exerciseDate>
                <footnoteId id="F2"/>
            </exerciseDate>
            <expirationDate>
                <footnoteId id="F2"/>
            </expirationDate>
            <underlyingSecurity>
                <underlyingSecurityTitle>
                    <value>Common Shares</value>
                </underlyingSecurityTitle>
                <underlyingSecurityShares>
                    <value>99483</value>
                </underlyingSecurityShares>
            </underlyingSecurity>
            <postTransactionAmounts>
                <sharesOwnedFollowingTransaction>
                    <value>99483</value>
                </sharesOwnedFollowingTransaction>
            </postTransactionAmounts>
            <ownershipNature>
                <directOrIndirectOwnership>
                    <value>D</value>
                </directOrIndirectOwnership>
            </ownershipNature>
        </derivativeTransaction>
    </derivativeTable>

    <footnotes>
        <footnote id="F1">Each restricted stock unit represents a contingent right to receive one common share of the Issuer.</footnote>
        <footnote id="F2">The restricted stock units will vest in three annual installments, with 33.34% of the units vesting on May 9, 2017, 33.33% of the units vesting on May 9, 2018 and 33.33% of the units vesting on May 9, 2019, subject, with limited exceptions, to the Reporting Person's continued employment with the Issuer or any of its subsidiaries.</footnote>
        <footnote id="F3">Pursuant to the Agreement and Plan of Merger, dated as of June 14, 2016, by and among the Issuer, Aegerion Pharmaceuticals, Inc. (&quot;Aegerion&quot;) and Isotope Acquisition Corp. (&quot;Isotope&quot;), pursuant to which Isotope was merged with and into Aegerion, effective on November 29, 2016, each restricted stock unit with respect to common stock of Aegerion (&quot;Aegerion RSU&quot;) that was outstanding as of immediately prior to the effective time of the merger was exchanged for a restricted stock unit with respect to a number of common shares of the Issuer (&quot;Issuer RSU&quot;) equal to the product obtained by multiplying (i) the total number of shares of common stock of Aegerion subject to the Aegerion RSU immediately prior to the effective time of the merger by (ii) the exchange ratio of 1.0256.</footnote>
        <footnote id="F4">Each Issuer RSU is subject to the same terms and conditions applicable to the corresponding Aegerion RSU and the agreements evidencing grant of the Aegerion RSUs thereunder, including vesting terms, but excluding any terms that are rendered inoperative solely by reason of the merger.</footnote>
    </footnotes>

    <ownerSignature>
        <signatureName>/s/ Jennifer Fitzpatrick, Attorney-in-fact</signatureName>
        <signatureDate>2016-12-01</signatureDate>
    </ownerSignature>
</ownershipDocument>
