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

    <schemaVersion>X0201</schemaVersion>

    <documentType>4</documentType>

    <periodOfReport>2004-02-23</periodOfReport>

    <notSubjectToSection16>0</notSubjectToSection16>

    <issuer>
        <issuerCik>0000851560</issuerCik>
        <issuerName>TARANTELLA INC</issuerName>
        <issuerTradingSymbol>TTLA</issuerTradingSymbol>
    </issuer>

    <reportingOwner>
        <reportingOwnerId>
            <rptOwnerCik>0001044321</rptOwnerCik>
            <rptOwnerName>MARXE AUSTIN W &amp; GREENHOUSE DAVID M</rptOwnerName>
        </reportingOwnerId>
        <reportingOwnerAddress>
            <rptOwnerStreet1>153 E 53RD ST</rptOwnerStreet1>
            <rptOwnerStreet2>55TH FL</rptOwnerStreet2>
            <rptOwnerCity>NEW YORK</rptOwnerCity>
            <rptOwnerState>NY</rptOwnerState>
            <rptOwnerZipCode>10022</rptOwnerZipCode>
            <rptOwnerStateDescription></rptOwnerStateDescription>
        </reportingOwnerAddress>
        <reportingOwnerRelationship>
            <isDirector>0</isDirector>
            <isOfficer>0</isOfficer>
            <isTenPercentOwner>1</isTenPercentOwner>
            <isOther>0</isOther>
        </reportingOwnerRelationship>
    </reportingOwner>

    <nonDerivativeTable>
        <nonDerivativeTransaction>
            <securityTitle>
                <value>Common Stock</value>
            </securityTitle>
            <transactionDate>
                <value>2004-02-23</value>
            </transactionDate>
            <transactionCoding>
                <transactionFormType>4</transactionFormType>
                <transactionCode>P</transactionCode>
                <equitySwapInvolved>0</equitySwapInvolved>
            </transactionCoding>
            <transactionTimeliness>
                <value></value>
            </transactionTimeliness>
            <transactionAmounts>
                <transactionShares>
                    <value>1200000</value>
                    <footnoteId id="F1"/>
                </transactionShares>
                <transactionPricePerShare>
                    <value>1.4</value>
                </transactionPricePerShare>
                <transactionAcquiredDisposedCode>
                    <value>A</value>
                </transactionAcquiredDisposedCode>
            </transactionAmounts>
            <postTransactionAmounts>
                <sharesOwnedFollowingTransaction>
                    <value>6794771</value>
                    <footnoteId id="F1"/>
                </sharesOwnedFollowingTransaction>
            </postTransactionAmounts>
            <ownershipNature>
                <directOrIndirectOwnership>
                    <value>I</value>
                    <footnoteId id="F1"/>
                </directOrIndirectOwnership>
                <natureOfOwnership>
                    <value>By Limited Partnerships</value>
                    <footnoteId id="F1"/>
                </natureOfOwnership>
            </ownershipNature>
        </nonDerivativeTransaction>
    </nonDerivativeTable>

    <derivativeTable>
        <derivativeTransaction>
            <securityTitle>
                <value>Warrants</value>
            </securityTitle>
            <conversionOrExercisePrice>
                <value>1.7</value>
            </conversionOrExercisePrice>
            <transactionDate>
                <value>2004-02-23</value>
            </transactionDate>
            <transactionCoding>
                <transactionFormType>4</transactionFormType>
                <transactionCode>P</transactionCode>
                <equitySwapInvolved>0</equitySwapInvolved>
            </transactionCoding>
            <transactionTimeliness>
                <value></value>
            </transactionTimeliness>
            <transactionAmounts>
                <transactionShares>
                    <value>240000</value>
                </transactionShares>
                <transactionPricePerShare>
                    <value>1.7</value>
                </transactionPricePerShare>
                <transactionAcquiredDisposedCode>
                    <value>A</value>
                </transactionAcquiredDisposedCode>
            </transactionAmounts>
            <exerciseDate>
                <value>2004-02-23</value>
                <footnoteId id="F2"/>
            </exerciseDate>
            <expirationDate>
                <value>2009-02-23</value>
            </expirationDate>
            <underlyingSecurity>
                <underlyingSecurityTitle>
                    <value>Common Stock</value>
                </underlyingSecurityTitle>
                <underlyingSecurityShares>
                    <value>240000</value>
                </underlyingSecurityShares>
            </underlyingSecurity>
            <postTransactionAmounts>
                <sharesOwnedFollowingTransaction>
                    <value>2102500</value>
                </sharesOwnedFollowingTransaction>
            </postTransactionAmounts>
            <ownershipNature>
                <directOrIndirectOwnership>
                    <value>I</value>
                </directOrIndirectOwnership>
                <natureOfOwnership>
                    <value>By Limited Partnerships</value>
                </natureOfOwnership>
            </ownershipNature>
        </derivativeTransaction>
    </derivativeTable>

    <footnotes>
        <footnote id="F1">This is a joint filing by Austin W. Marxe (Marxe) and David M. Greenhouse (Greenhouse).  They share voting and investment control over all securities owned by  Special Situations Cayman Fund, L.P. (CAY), Special Situations Private Equity Fund, L.P. (SSPE), Special Situations Technology Fund, LP (Tech) and Special Situations Technology II, LP. (Tech II), respectively. 600,000 shares of Common Stock and 120,000 Wts are held by CAY, 600,000 shares of Common Stock and 120,000 Wts are held by SSPE, 571,771 shares of Common Stock , 239,500 Wts and 65,460 Wts are held by Tech and 2,920,500 shares of Common Stock, 1,223,000 Wts and 334,540 wts are held by Tech II.  The interest of Marxe and Greenhouse in the shares of Common Stock owned by CAY, SSPE,  Tech and Tech II is limited to the extent of his pecuniary interest.</footnote>
        <footnote id="F2">Subject to the effective date of form S-3 to be filed by the Issuer.</footnote>
    </footnotes>

    <ownerSignature>
        <signatureName>Austin W. Marxe</signatureName>
        <signatureDate>2004-02-25</signatureDate>
    </ownerSignature>

    <ownerSignature>
        <signatureName>David M. Greenhouse</signatureName>
        <signatureDate>2004-02-25</signatureDate>
    </ownerSignature>
</ownershipDocument>

