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

    <schemaVersion>X0202</schemaVersion>

    <documentType>4</documentType>

    <periodOfReport>2006-05-22</periodOfReport>

    <notSubjectToSection16>0</notSubjectToSection16>

    <issuer>
        <issuerCik>0001075880</issuerCik>
        <issuerName>NOVOGEN LTD</issuerName>
        <issuerTradingSymbol>NVGN</issuerTradingSymbol>
    </issuer>

    <reportingOwner>
        <reportingOwnerId>
            <rptOwnerCik>0000932267</rptOwnerCik>
            <rptOwnerName>AUSTIN JOSIAH T</rptOwnerName>
        </reportingOwnerId>
        <reportingOwnerAddress>
            <rptOwnerStreet1>EL CORONADO RANCH</rptOwnerStreet1>
            <rptOwnerStreet2>12626 TURKEY CREEK ROAD</rptOwnerStreet2>
            <rptOwnerCity>PEARCE</rptOwnerCity>
            <rptOwnerState>AZ</rptOwnerState>
            <rptOwnerZipCode>85625</rptOwnerZipCode>
            <rptOwnerStateDescription></rptOwnerStateDescription>
        </reportingOwnerAddress>
        <reportingOwnerRelationship>
            <isDirector>0</isDirector>
            <isOfficer>0</isOfficer>
            <isTenPercentOwner>1</isTenPercentOwner>
            <isOther>0</isOther>
        </reportingOwnerRelationship>
    </reportingOwner>

    <reportingOwner>
        <reportingOwnerId>
            <rptOwnerCik>0001319763</rptOwnerCik>
            <rptOwnerName>El Coronado Holdings, LLC</rptOwnerName>
        </reportingOwnerId>
        <reportingOwnerAddress>
            <rptOwnerStreet1>12626 TURKEY CREEK ROAD</rptOwnerStreet1>
            <rptOwnerStreet2></rptOwnerStreet2>
            <rptOwnerCity>PEARCE</rptOwnerCity>
            <rptOwnerState>AZ</rptOwnerState>
            <rptOwnerZipCode>85625</rptOwnerZipCode>
            <rptOwnerStateDescription></rptOwnerStateDescription>
        </reportingOwnerAddress>
        <reportingOwnerRelationship>
            <isDirector>0</isDirector>
            <isOfficer>0</isOfficer>
            <isTenPercentOwner>1</isTenPercentOwner>
            <isOther>0</isOther>
        </reportingOwnerRelationship>
    </reportingOwner>

    <nonDerivativeTable>
        <nonDerivativeTransaction>
            <securityTitle>
                <value>Sponsored ADRs, each convertible into 5 ordinary shares</value>
            </securityTitle>
            <transactionDate>
                <value>2006-05-22</value>
            </transactionDate>
            <transactionCoding>
                <transactionFormType>4</transactionFormType>
                <transactionCode>P</transactionCode>
                <equitySwapInvolved>0</equitySwapInvolved>
            </transactionCoding>
            <transactionTimeliness>
                <value></value>
            </transactionTimeliness>
            <transactionAmounts>
                <transactionShares>
                    <value>4900</value>
                    <footnoteId id="F1"/>
                </transactionShares>
                <transactionPricePerShare>
                    <value>10.047</value>
                </transactionPricePerShare>
                <transactionAcquiredDisposedCode>
                    <value>A</value>
                </transactionAcquiredDisposedCode>
            </transactionAmounts>
            <postTransactionAmounts>
                <sharesOwnedFollowingTransaction>
                    <value>2112942</value>
                    <footnoteId id="F2"/>
                </sharesOwnedFollowingTransaction>
            </postTransactionAmounts>
            <ownershipNature>
                <directOrIndirectOwnership>
                    <value>I</value>
                </directOrIndirectOwnership>
                <natureOfOwnership>
                    <value>As Managing Member of El Coronado Holdings, LLC</value>
                </natureOfOwnership>
            </ownershipNature>
        </nonDerivativeTransaction>
    </nonDerivativeTable>

    <footnotes>
        <footnote id="F1">(representing 24,500 Ordinary Shares)</footnote>
        <footnote id="F2">(representing 10,564,710 Ordinary Shares)</footnote>
    </footnotes>

    <remarks>This report is filed jointly on behalf of Mr. Austin and El Coronado Holdings, LLC (&quot;ECH&quot;), an Arizona limited liability company of which Mr. Austin is the sole managing member.
The address of ECH is 12626 Turkey Creek Road, Pearce, AZ 85625.  ECH owns directly 2,085,942 Sponsored ADRs (representing 10,429,710 Ordinary Shares).</remarks>

    <ownerSignature>
        <signatureName>Josiah T. Austin, Individually, and as Managing Member of ECH</signatureName>
        <signatureDate>2006-05-23</signatureDate>
    </ownerSignature>
</ownershipDocument>
