<SUBMISSION>
<ACCESSION-NUMBER>0001453356-09-000014
<TYPE>4
<PUBLIC-DOCUMENT-COUNT>1
<PERIOD>20090930
<FILING-DATE>20091006
<DATE-OF-FILING-DATE-CHANGE>20091006
<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>
<REPORTING-OWNER>
<OWNER-DATA>
<CONFORMED-NAME>10X Fund, L.P.
<CIK>0001453356
<STATE-OF-INCORPORATION>DE
<FISCAL-YEAR-END>1231
</OWNER-DATA>
<FILING-VALUES>
<FORM-TYPE>4
<ACT>34
<FILE-NUMBER>001-31791
<FILM-NUMBER>091108847
</FILING-VALUES>
<BUSINESS-ADDRESS>
<STREET1>1099 FOREST LAKE TERRACE
<CITY>NICEVILLE
<STATE>FL
<ZIP>32578
<PHONE>208-263-6695
</BUSINESS-ADDRESS>
<MAIL-ADDRESS>
<STREET1>1099 FOREST LAKE TERRACE
<CITY>NICEVILLE
<STATE>FL
<ZIP>32578
</MAIL-ADDRESS>
<FORMER-NAME>
<FORMER-CONFORMED-NAME>10X FUND LP
<DATE-CHANGED>20090107
</FORMER-NAME>
</REPORTING-OWNER>
<REPORTING-OWNER>
<OWNER-DATA>
<CONFORMED-NAME>10X Capital Management, LLC
<CIK>0001457247
<STATE-OF-INCORPORATION>FL
<FISCAL-YEAR-END>1231
</OWNER-DATA>
<FILING-VALUES>
<FORM-TYPE>4
<ACT>34
<FILE-NUMBER>001-31791
<FILM-NUMBER>091108846
</FILING-VALUES>
<BUSINESS-ADDRESS>
<STREET1>1099 FOREST LAKE TERRACE
<CITY>NICEVILLE
<STATE>FL
<ZIP>32578
<PHONE>850-502-7659
</BUSINESS-ADDRESS>
<MAIL-ADDRESS>
<STREET1>1099 FOREST LAKE TERRACE
<CITY>NICEVILLE
<STATE>FL
<ZIP>32578
</MAIL-ADDRESS>
</REPORTING-OWNER>
<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>2009-09-30</periodOfReport>

    <notSubjectToSection16>0</notSubjectToSection16>

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

    <reportingOwner>
        <reportingOwnerId>
            <rptOwnerCik>0001453356</rptOwnerCik>
            <rptOwnerName>10X Fund, L.P.</rptOwnerName>
        </reportingOwnerId>
        <reportingOwnerAddress>
            <rptOwnerStreet1>1099 FOREST LAKE TERRACE</rptOwnerStreet1>
            <rptOwnerStreet2></rptOwnerStreet2>
            <rptOwnerCity>NICEVILLE</rptOwnerCity>
            <rptOwnerState>FL</rptOwnerState>
            <rptOwnerZipCode>32578</rptOwnerZipCode>
            <rptOwnerStateDescription></rptOwnerStateDescription>
        </reportingOwnerAddress>
        <reportingOwnerRelationship>
            <isDirector>0</isDirector>
            <isOfficer>0</isOfficer>
            <isTenPercentOwner>1</isTenPercentOwner>
            <isOther>0</isOther>
        </reportingOwnerRelationship>
    </reportingOwner>

    <reportingOwner>
        <reportingOwnerId>
            <rptOwnerCik>0001457247</rptOwnerCik>
            <rptOwnerName>10X Capital Management, LLC</rptOwnerName>
        </reportingOwnerId>
        <reportingOwnerAddress>
            <rptOwnerStreet1>1099 FOREST LAKE TERRACE</rptOwnerStreet1>
            <rptOwnerStreet2></rptOwnerStreet2>
            <rptOwnerCity>NICEVILLE</rptOwnerCity>
            <rptOwnerState>FL</rptOwnerState>
            <rptOwnerZipCode>32578</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>2009-09-30</value>
            </transactionDate>
            <transactionCoding>
                <transactionFormType>4</transactionFormType>
                <transactionCode>A</transactionCode>
                <equitySwapInvolved>0</equitySwapInvolved>
                <footnoteId id="F1"/>
            </transactionCoding>
            <transactionTimeliness>
                <value></value>
            </transactionTimeliness>
            <transactionAmounts>
                <transactionShares>
                    <value>213136</value>
                </transactionShares>
                <transactionPricePerShare>
                    <value>0.5</value>
                    <footnoteId id="F1"/>
                </transactionPricePerShare>
                <transactionAcquiredDisposedCode>
                    <value>A</value>
                </transactionAcquiredDisposedCode>
            </transactionAmounts>
            <postTransactionAmounts>
                <sharesOwnedFollowingTransaction>
                    <value>420804</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>

    <derivativeTable>
        <derivativeTransaction>
            <securityTitle>
                <value>Series B-2 Convertible Preferred Stock</value>
            </securityTitle>
            <conversionOrExercisePrice>
                <value>0.5</value>
            </conversionOrExercisePrice>
            <transactionDate>
                <value>2009-09-30</value>
            </transactionDate>
            <transactionCoding>
                <transactionFormType>4</transactionFormType>
                <transactionCode>P</transactionCode>
                <equitySwapInvolved>0</equitySwapInvolved>
            </transactionCoding>
            <transactionTimeliness>
                <value></value>
            </transactionTimeliness>
            <transactionAmounts>
                <transactionShares>
                    <value>162500</value>
                </transactionShares>
                <transactionPricePerShare>
                    <value>2</value>
                    <footnoteId id="F5"/>
                </transactionPricePerShare>
                <transactionAcquiredDisposedCode>
                    <value>A</value>
                </transactionAcquiredDisposedCode>
            </transactionAmounts>
            <exerciseDate>
                <footnoteId id="F4"/>
            </exerciseDate>
            <expirationDate>
                <footnoteId id="F4"/>
            </expirationDate>
            <underlyingSecurity>
                <underlyingSecurityTitle>
                    <value>Common Stock</value>
                </underlyingSecurityTitle>
                <underlyingSecurityShares>
                    <value>650000</value>
                </underlyingSecurityShares>
            </underlyingSecurity>
            <postTransactionAmounts>
                <sharesOwnedFollowingTransaction>
                    <value>1012500</value>
                </sharesOwnedFollowingTransaction>
            </postTransactionAmounts>
            <ownershipNature>
                <directOrIndirectOwnership>
                    <value>I</value>
                    <footnoteId id="F2"/>
                </directOrIndirectOwnership>
                <natureOfOwnership>
                    <value>By 10X Fund, LP</value>
                    <footnoteId id="F2"/>
                    <footnoteId id="F3"/>
                    <footnoteId id="F6"/>
                </natureOfOwnership>
            </ownershipNature>
        </derivativeTransaction>
        <derivativeTransaction>
            <securityTitle>
                <value>Class A-1 Warrant (right to buy)</value>
            </securityTitle>
            <conversionOrExercisePrice>
                <value>0.5</value>
            </conversionOrExercisePrice>
            <transactionDate>
                <value>2009-09-30</value>
            </transactionDate>
            <transactionCoding>
                <transactionFormType>4</transactionFormType>
                <transactionCode>P</transactionCode>
                <equitySwapInvolved>0</equitySwapInvolved>
            </transactionCoding>
            <transactionTimeliness>
                <value></value>
            </transactionTimeliness>
            <transactionAmounts>
                <transactionShares>
                    <value>1</value>
                </transactionShares>
                <transactionPricePerShare>
                    <value>0</value>
                    <footnoteId id="F5"/>
                </transactionPricePerShare>
                <transactionAcquiredDisposedCode>
                    <value>A</value>
                </transactionAcquiredDisposedCode>
            </transactionAmounts>
            <exerciseDate>
                <value>2009-09-30</value>
            </exerciseDate>
            <expirationDate>
                <value>2014-09-30</value>
            </expirationDate>
            <underlyingSecurity>
                <underlyingSecurityTitle>
                    <value>Common Stock</value>
                </underlyingSecurityTitle>
                <underlyingSecurityShares>
                    <value>325000</value>
                </underlyingSecurityShares>
            </underlyingSecurity>
            <postTransactionAmounts>
                <sharesOwnedFollowingTransaction>
                    <value>5</value>
                </sharesOwnedFollowingTransaction>
            </postTransactionAmounts>
            <ownershipNature>
                <directOrIndirectOwnership>
                    <value>I</value>
                    <footnoteId id="F2"/>
                </directOrIndirectOwnership>
                <natureOfOwnership>
                    <value>By 10X Fund, LP</value>
                    <footnoteId id="F2"/>
                    <footnoteId id="F3"/>
                    <footnoteId id="F6"/>
                </natureOfOwnership>
            </ownershipNature>
        </derivativeTransaction>
        <derivativeTransaction>
            <securityTitle>
                <value>Class A-2 Warrant (right to buy)</value>
            </securityTitle>
            <conversionOrExercisePrice>
                <value>0.5</value>
            </conversionOrExercisePrice>
            <transactionDate>
                <value>2009-09-30</value>
            </transactionDate>
            <transactionCoding>
                <transactionFormType>4</transactionFormType>
                <transactionCode>P</transactionCode>
                <equitySwapInvolved>0</equitySwapInvolved>
            </transactionCoding>
            <transactionTimeliness>
                <value></value>
            </transactionTimeliness>
            <transactionAmounts>
                <transactionShares>
                    <value>1</value>
                </transactionShares>
                <transactionPricePerShare>
                    <value>0</value>
                    <footnoteId id="F5"/>
                </transactionPricePerShare>
                <transactionAcquiredDisposedCode>
                    <value>A</value>
                </transactionAcquiredDisposedCode>
            </transactionAmounts>
            <exerciseDate>
                <value>2009-09-30</value>
            </exerciseDate>
            <expirationDate>
                <value>2014-09-30</value>
            </expirationDate>
            <underlyingSecurity>
                <underlyingSecurityTitle>
                    <value>Common Stock</value>
                </underlyingSecurityTitle>
                <underlyingSecurityShares>
                    <value>325000</value>
                </underlyingSecurityShares>
            </underlyingSecurity>
            <postTransactionAmounts>
                <sharesOwnedFollowingTransaction>
                    <value>5</value>
                </sharesOwnedFollowingTransaction>
            </postTransactionAmounts>
            <ownershipNature>
                <directOrIndirectOwnership>
                    <value>I</value>
                    <footnoteId id="F2"/>
                </directOrIndirectOwnership>
                <natureOfOwnership>
                    <value>By 10X Fund, LP</value>
                    <footnoteId id="F2"/>
                    <footnoteId id="F3"/>
                    <footnoteId id="F6"/>
                </natureOfOwnership>
            </ownershipNature>
        </derivativeTransaction>
        <derivativeTransaction>
            <securityTitle>
                <value>Class B Warrant (right to buy)</value>
            </securityTitle>
            <conversionOrExercisePrice>
                <value>0.5</value>
            </conversionOrExercisePrice>
            <transactionDate>
                <value>2009-09-30</value>
            </transactionDate>
            <transactionCoding>
                <transactionFormType>4</transactionFormType>
                <transactionCode>P</transactionCode>
                <equitySwapInvolved>0</equitySwapInvolved>
            </transactionCoding>
            <transactionTimeliness>
                <value></value>
            </transactionTimeliness>
            <transactionAmounts>
                <transactionShares>
                    <value>1</value>
                </transactionShares>
                <transactionPricePerShare>
                    <value>0</value>
                    <footnoteId id="F5"/>
                </transactionPricePerShare>
                <transactionAcquiredDisposedCode>
                    <value>A</value>
                </transactionAcquiredDisposedCode>
            </transactionAmounts>
            <exerciseDate>
                <value>2009-09-30</value>
            </exerciseDate>
            <expirationDate>
                <value>2014-09-30</value>
            </expirationDate>
            <underlyingSecurity>
                <underlyingSecurityTitle>
                    <value>Common Stock</value>
                </underlyingSecurityTitle>
                <underlyingSecurityShares>
                    <value>1300000</value>
                </underlyingSecurityShares>
            </underlyingSecurity>
            <postTransactionAmounts>
                <sharesOwnedFollowingTransaction>
                    <value>5</value>
                </sharesOwnedFollowingTransaction>
            </postTransactionAmounts>
            <ownershipNature>
                <directOrIndirectOwnership>
                    <value>I</value>
                    <footnoteId id="F2"/>
                </directOrIndirectOwnership>
                <natureOfOwnership>
                    <value>By 10X Fund, LP</value>
                    <footnoteId id="F2"/>
                    <footnoteId id="F3"/>
                    <footnoteId id="F6"/>
                </natureOfOwnership>
            </ownershipNature>
        </derivativeTransaction>
    </derivativeTable>

    <footnotes>
        <footnote id="F1">On September 30, 2009, 10X Fund, L.P. received 213,136 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">10X Fund, L.P. has direct beneficial ownership of all the securities owned by 10X Fund, L.P.  10X Capital Management, LLC, a Florida limited liability company, is the general partner of 10X Fund, L.P., a Delaware limited partnership, and 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">10X Capital Management, LLC disclaims beneficial ownership of the reported securities except to the extent of its pecuniary interest therein.</footnote>
        <footnote id="F4">Each share of Series B-2 Convertible Preferred Stock is convertible into four shares of Issuer's common stock at a conversion price of $0.50 per share (subject to customary anti-dilution protection adjustments) at the option of (a) the holder, at any time and (b) Issuer, at any time after September 30, 2010 (and upon 10 days notice) if the Issuer's common stock is quoted at or above $1.50 per share for 15 consecutive trading days and an effective registration statement regarding the underlying shares of Issuer's common stock is in effect (subject to certain monthly volume limits).  The shares of Series B-2 Convertible Preferred Stock do not expire.</footnote>
        <footnote id="F5">On September 30, 2009, 10X Fund, L.P. purchased (a) 162,500 shares of Series B-2 Preferred Stock, (b) one Class A-1 Warrant to purchase 325,000 shares of Common Stock for $0.50 per share, (c) one Class A-2 Warrant to purchase 325,000 shares of Common Stock for $0.50 per share, and (d) one Class B Warrant to purchase 1,300,000 shares of Common Stock for $0.50 per share, for aggregate consideration of $325,000.</footnote>
        <footnote id="F6">Excludes (i) up to 1,087,500 shares of Series B-2 Preferred Stock convertible into 4,350,000 shares of Common Stock; (ii) Class A-1 Warrants exercisable to purchase up to 2,175,000 shares of Common Stock; (iii) Class A-2 Warrants exercisable to purchase up to 2,175,000 shares of Common Stock; and (iv) Class B Warrants exercisable to purchase up to 8,700,000 shares of Common Stock that 10X Fund, L.P. may purchase from Issuer within 60 days of the date hereof pursuant to a Securities Purchase Agreement dated February 12, 2009, as amended on August 11, 2009, between Issuer and 10X Fund, L.P.</footnote>
    </footnotes>

    <remarks>This statement is a joint filing by 10X Fund, L.P. and 10X Capital Management, LLC, a Florida limited liability company and the general partner of 10X Fund, L.P.</remarks>

    <ownerSignature>
        <signatureName>/s/ Robert J. Mottern, as attorney in fact for 10X Fund, L.P.</signatureName>
        <signatureDate>2009-10-06</signatureDate>
    </ownerSignature>

    <ownerSignature>
        <signatureName>/s/ Robert J. Mottern, as attorney in fact for 10X Capital Management, LLC</signatureName>
        <signatureDate>2009-10-06</signatureDate>
    </ownerSignature>
</ownershipDocument>
</XML>
</TEXT>
</DOCUMENT>
</SUBMISSION>
