<SUBMISSION>
<ACCESSION-NUMBER>0001238252-03-000001
<TYPE>4
<PUBLIC-DOCUMENT-COUNT>1
<PERIOD>20031229
<FILING-DATE>20031230
<ISSUER>
<COMPANY-DATA>
<CONFORMED-NAME>SONUS PHARMACEUTICALS INC
<CIK>0000949858
<ASSIGNED-SIC>2835
<IRS-NUMBER>954343413
<STATE-OF-INCORPORATION>DE
<FISCAL-YEAR-END>1231
</COMPANY-DATA>
<BUSINESS-ADDRESS>
<STREET1>22026 2OTH AVE SE
<STREET2>STE 102
<CITY>BOTHELL
<STATE>WA
<ZIP>98021
<PHONE>2064879500
</BUSINESS-ADDRESS>
<MAIL-ADDRESS>
<STREET1>22026 20TH AVENUE SE, SUITE 102
<CITY>BOTHELL
<STATE>WA
<ZIP>98021
</MAIL-ADDRESS>
</ISSUER>
<REPORTING-OWNER>
<OWNER-DATA>
<CONFORMED-NAME>KLEIN RICHARD J
<CIK>0001238252
</OWNER-DATA>
<FILING-VALUES>
<FORM-TYPE>4
<ACT>34
<FILE-NUMBER>000-21243
<FILM-NUMBER>031078230
</FILING-VALUES>
<BUSINESS-ADDRESS>
<STREET1>SONUS PHARMACEUTICALS INC
<STREET2>22026 20TH AVE SE
<CITY>BOTHELL
<STATE>WA
<ZIP>98021
<PHONE>4254879500
</BUSINESS-ADDRESS>
<MAIL-ADDRESS>
<STREET1>22026 20TH AVENUE SE
<CITY>BOTHELL
<STATE>WA
<ZIP>98021
</MAIL-ADDRESS>
</REPORTING-OWNER>
<DOCUMENT>
<TYPE>4
<SEQUENCE>1
<FILENAME>primary_doc.xml
<DESCRIPTION>PRIMARY DOCUMENT
<TEXT>
<XML>
<?xml version="1.0"?>

<ownershipDocument>

    <schemaVersion>X0201</schemaVersion>

    <documentType>4</documentType>

    <periodOfReport>2003-12-29</periodOfReport>


    <notSubjectToSection16>0</notSubjectToSection16>

    <issuer>
        <issuerCik>0000949858</issuerCik>
        <issuerName>SONUS PHARMACEUTICALS INC</issuerName>
        <issuerTradingSymbol>SNUS</issuerTradingSymbol>
    </issuer>

    <reportingOwner>
        <reportingOwnerId>
            <rptOwnerCik>0001238252</rptOwnerCik>
            <rptOwnerName>KLEIN RICHARD J</rptOwnerName>
        </reportingOwnerId>
        <reportingOwnerAddress>
            <rptOwnerStreet1>22026 20TH AVENUE SE</rptOwnerStreet1>
            <rptOwnerStreet2></rptOwnerStreet2>
            <rptOwnerCity>BOTHELL</rptOwnerCity>
            <rptOwnerState>WA</rptOwnerState>
            <rptOwnerZipCode>98021</rptOwnerZipCode>
            <rptOwnerStateDescription></rptOwnerStateDescription>
        </reportingOwnerAddress>
        <reportingOwnerRelationship>
            <isDirector>0</isDirector>
            <isOfficer>1</isOfficer>
            <isTenPercentOwner>0</isTenPercentOwner>
            <isOther>0</isOther>
            <officerTitle>Senior V.P. &amp; CFO</officerTitle>
        </reportingOwnerRelationship>
    </reportingOwner>

    <derivativeTable>

        <derivativeTransaction>
            <securityTitle>
                <value>Employee Non-qualified Stock Option (right to buy)</value>
            </securityTitle>
            <conversionOrExercisePrice>
                <value>5.01</value>
            </conversionOrExercisePrice>
            <transactionDate>
                <value>2003-12-29</value>
            </transactionDate>
            <transactionCoding>
                <transactionFormType>4</transactionFormType>
                <transactionCode>A</transactionCode>
                <equitySwapInvolved>0</equitySwapInvolved>
            </transactionCoding>
            <transactionTimeliness>
                <value></value>
            </transactionTimeliness>
            <transactionAmounts>
                <transactionShares>
                    <value>80000</value>
                </transactionShares>
                <transactionPricePerShare>
                    <value>0</value>
                </transactionPricePerShare>
                <transactionAcquiredDisposedCode>
                    <value>A</value>
                </transactionAcquiredDisposedCode>
            </transactionAmounts>
            <exerciseDate>
                <value>2004-12-29</value>
                <footnoteId id="F1"/>
            </exerciseDate>
            <expirationDate>
                <value>2013-12-29</value>
            </expirationDate>
            <underlyingSecurity>
                <underlyingSecurityTitle>
                    <value>Common Stock</value>
                </underlyingSecurityTitle>
                <underlyingSecurityShares>
                    <value>80000</value>
                </underlyingSecurityShares>
            </underlyingSecurity>
            <postTransactionAmounts>
                <sharesOwnedFollowingTransaction>
                    <value>80000</value>
                </sharesOwnedFollowingTransaction>
            </postTransactionAmounts>
            <ownershipNature>
                <directOrIndirectOwnership>
                    <value>D</value>
                </directOrIndirectOwnership>
            </ownershipNature>
        </derivativeTransaction>

    </derivativeTable>

    <footnotes>
        <footnote id="F1">25% of options become exercisable on the first anniversary of the date of grant and the remainder vest over the next three succeeding years in equal monthly installments.</footnote>
    </footnotes>


    <ownerSignature>
        <signatureName>/s/Richard J. Klein</signatureName>
        <signatureDate>2003-12-30</signatureDate>
    </ownerSignature>

</ownershipDocument>

</XML>
</TEXT>
</DOCUMENT>
</SUBMISSION>
