<SUBMISSION>
<ACCESSION-NUMBER>0001260641-09-000017
<TYPE>4
<PUBLIC-DOCUMENT-COUNT>1
<PERIOD>20090821
<FILING-DATE>20090824
<DATE-OF-FILING-DATE-CHANGE>20090824
<REPORTING-OWNER>
<OWNER-DATA>
<CONFORMED-NAME>CZIRR JAMES C
<CIK>0001260641
</OWNER-DATA>
<FILING-VALUES>
<FORM-TYPE>4
<ACT>34
<FILE-NUMBER>001-31791
<FILM-NUMBER>091032242
</FILING-VALUES>
<MAIL-ADDRESS>
<STREET1>425 JANISH DR
<CITY>SANDPOINT
<STATE>ID
<ZIP>83864
</MAIL-ADDRESS>
</REPORTING-OWNER>
<ISSUER>
<COMPANY-DATA>
<CONFORMED-NAME>PRO PHARMACEUTICALS INC
<CIK>0001133416
<ASSIGNED-SIC>2834
<IRS-NUMBER>043562325
<STATE-OF-INCORPORATION>NV
<FISCAL-YEAR-END>1231
</COMPANY-DATA>
<BUSINESS-ADDRESS>
<STREET1>189 WELLS ST
<STREET2>STE 200
<CITY>NEWTON
<STATE>MA
<ZIP>02459
<PHONE>6175590033
</BUSINESS-ADDRESS>
<MAIL-ADDRESS>
<STREET1>189 WELLS ST
<STREET2>STE 200
<CITY>NEWTON
<STATE>MA
<ZIP>02459
</MAIL-ADDRESS>
</ISSUER>
<DOCUMENT>
<TYPE>4
<SEQUENCE>1
<FILENAME>primary_doc.xml
<DESCRIPTION>PRIMARY DOCUMENT
<TEXT>
<XML>
<?xml version="1.0"?>
<ownershipDocument>

    <schemaVersion>X0303</schemaVersion>

    <documentType>4</documentType>

    <periodOfReport>2009-08-21</periodOfReport>

    <notSubjectToSection16>0</notSubjectToSection16>

    <issuer>
        <issuerCik>0001133416</issuerCik>
        <issuerName>PRO PHARMACEUTICALS INC</issuerName>
        <issuerTradingSymbol>PRWP</issuerTradingSymbol>
    </issuer>

    <reportingOwner>
        <reportingOwnerId>
            <rptOwnerCik>0001260641</rptOwnerCik>
            <rptOwnerName>CZIRR JAMES C</rptOwnerName>
        </reportingOwnerId>
        <reportingOwnerAddress>
            <rptOwnerStreet1>425 JANISH DR</rptOwnerStreet1>
            <rptOwnerStreet2></rptOwnerStreet2>
            <rptOwnerCity>SANDPOINT</rptOwnerCity>
            <rptOwnerState>ID</rptOwnerState>
            <rptOwnerZipCode>83864</rptOwnerZipCode>
            <rptOwnerStateDescription></rptOwnerStateDescription>
        </reportingOwnerAddress>
        <reportingOwnerRelationship>
            <isDirector>1</isDirector>
            <isOfficer>0</isOfficer>
            <isTenPercentOwner>1</isTenPercentOwner>
            <isOther>0</isOther>
        </reportingOwnerRelationship>
    </reportingOwner>

    <nonDerivativeTable>
        <nonDerivativeTransaction>
            <securityTitle>
                <value>Common Stock</value>
            </securityTitle>
            <transactionDate>
                <value>2009-08-21</value>
            </transactionDate>
            <transactionCoding>
                <transactionFormType>4</transactionFormType>
                <transactionCode>A</transactionCode>
                <equitySwapInvolved>0</equitySwapInvolved>
                <footnoteId id="F1"/>
            </transactionCoding>
            <transactionTimeliness>
                <value></value>
            </transactionTimeliness>
            <transactionAmounts>
                <transactionShares>
                    <value>207668</value>
                </transactionShares>
                <transactionPricePerShare>
                    <value>0.5</value>
                    <footnoteId id="F1"/>
                </transactionPricePerShare>
                <transactionAcquiredDisposedCode>
                    <value>A</value>
                </transactionAcquiredDisposedCode>
            </transactionAmounts>
            <postTransactionAmounts>
                <sharesOwnedFollowingTransaction>
                    <value>207668</value>
                </sharesOwnedFollowingTransaction>
            </postTransactionAmounts>
            <ownershipNature>
                <directOrIndirectOwnership>
                    <value>I</value>
                </directOrIndirectOwnership>
                <natureOfOwnership>
                    <value>By 10X Fund, LP</value>
                    <footnoteId id="F2"/>
                    <footnoteId id="F3"/>
                </natureOfOwnership>
            </ownershipNature>
        </nonDerivativeTransaction>
    </nonDerivativeTable>

    <footnotes>
        <footnote id="F1">On August 21, 2009, 10X Fund, L.P. received 207,668 shares of Common Stock of the Issuer in satisfaction of dividends on shares of Series B-1 and B-2 Convertible Preferred Stock owned by 10X Fund, L.P.   Dividends on the Preferred Stock are payable in shares of the Issuer's Common Stock valued at $0.50 per share, with regard to the actual market price of the Common Stock at the time of issuance.  The market value of the Common Stock at the time of its issuance was less than $0.50 per share.</footnote>
        <footnote id="F2">Reporting Person is a managing member of 10X Capital Management, LLC, a Florida limited liability company acting as the general partner of 10X Fund, L.P., a Delaware limited partnership, and as such, may be deemed to have indirect beneficial ownership of all or a portion of the securities owned directly by 10X Fund, L.P., such portion being equal to 10X Capital Management, LLC's (a) 20% interest in the profits of 10X Fund, L.P., (b) interest in any securities which are used to pay a 2% annual management fee to 10X Capital Management, LLC, and (c) interest in one-half of the Class B Warrants acquired by 10X Fund, L.P. in all closings other than the initial closing held on February 12, 2009, less one Class B Warrant which 10X Capital Management, LLC has committed to reallocate to investors in all prior closings until each such investor has one (1) additional Class B Warrant for each dollar invested.</footnote>
        <footnote id="F3">Any such deemed indirect beneficial ownership may also be reduced by Mr. Czirr's proportional ownership in 10X Capital Management, LLC.  Mr. Czirr disclaims beneficial ownership of the reported securities except to the extent of his pecuniary interest therein.</footnote>
    </footnotes>

    <ownerSignature>
        <signatureName>/s/ Robert J. Mottern, as attorney in fact for James C. Czirr</signatureName>
        <signatureDate>2009-08-24</signatureDate>
    </ownerSignature>
</ownershipDocument>
</XML>
</TEXT>
</DOCUMENT>
</SUBMISSION>
