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

    <schemaVersion>X0101</schemaVersion>

<documentType>4</documentType>

    <periodOfReport>2003-05-14</periodOfReport>

    <notSubjectToSection16>0</notSubjectToSection16>

<issuer>        <issuerCik>0000877902</issuerCik>
        <issuerName>NEOSE TECHNOLOGIES INC</issuerName>
<issuerTradingSymbol>NTEC</issuerTradingSymbol>
    </issuer>

    <reportingOwner>
        <reportingOwnerId>
            <rptOwnerCik>0001196903</rptOwnerCik>
            <rptOwnerName>GAGE L PATRICK</rptOwnerName>
        </reportingOwnerId>
        <reportingOwnerAddress>
            <rptOwnerStreet1>  </rptOwnerStreet1>
            <rptOwnerStreet2>  </rptOwnerStreet2>
            <rptOwnerCity>  </rptOwnerCity>
            <rptOwnerState>  </rptOwnerState>
            <rptOwnerZipCode>  </rptOwnerZipCode>
        </reportingOwnerAddress>
<reportingOwnerRelationship>
            <isDirector>1</isDirector>
            <isOfficer>0</isOfficer>
            <isTenPercentOwner>0</isTenPercentOwner>
            <isOther>0</isOther>
        </reportingOwnerRelationship>
    </reportingOwner>

    <derivativeSecurity>
        <securityTitle>
            <value>Non-Qualified Stock Option (right to buy)</value>
        </securityTitle>
        <conversionOrExercisePrice>
            <value>3.26</value>
        </conversionOrExercisePrice>
        <transactionDate>
            <value>2003-05-13</value>
        </transactionDate>
        <transactionCoding>
            <transactionFormType>4</transactionFormType>
            <transactionCode>A</transactionCode>
            <equitySwapInvolved>0</equitySwapInvolved>
        </transactionCoding>
        <transactionAmounts>
            <transactionShares>
                <value>2147</value>
            </transactionShares>
            <transactionValue>
                <value>0</value>
            </transactionValue>
            <transactionAcquiredDisposedCode>
                <value>A</value>
            </transactionAcquiredDisposedCode>
        </transactionAmounts>
        <exerciseDate>
            <value>2003-05-13</value>
        </exerciseDate>
        <expirationDate>
            <value>2013-05-13</value>
        </expirationDate>
        <underlyingSecurity>
            <underlyingSecurityTitle>
                <value>Common Stock</value>
            </underlyingSecurityTitle>
            <underlyingSecurityShares>
                <value>2147</value>
            </underlyingSecurityShares>
        </underlyingSecurity>
        <postTransactionAmounts>
            <valueOwnedFollowingTransaction>
                <value>2147</value>
            </valueOwnedFollowingTransaction>
        </postTransactionAmounts>
        <ownershipNature>
            <directOrIndirectOwnership>
                <value>D</value>
            </directOrIndirectOwnership>
        </ownershipNature>
    </derivativeSecurity>

    <derivativeSecurity>
        <securityTitle>
            <value>Non-Qualified Stock Option (right to buy)</value>
        </securityTitle>
        <conversionOrExercisePrice>
            <value>9.78</value>
        </conversionOrExercisePrice>
        <transactionDate>
            <value>2003-05-13</value>
        </transactionDate>
        <transactionCoding>
            <transactionFormType>4</transactionFormType>
            <transactionCode>A</transactionCode>
            <equitySwapInvolved>0</equitySwapInvolved>
        </transactionCoding>
        <transactionAmounts>
            <transactionShares>
                <value>10000</value>
            </transactionShares>
            <transactionValue>
                <value>0</value>
            </transactionValue>
            <transactionAcquiredDisposedCode>
                <value>A</value>
            </transactionAcquiredDisposedCode>
        </transactionAmounts>
        <exerciseDate>
            <value>2003-05-13</value>
                <footnoteId id="F1"/>
        </exerciseDate>
        <expirationDate>
            <value>2013-05-13</value>
        </expirationDate>
        <underlyingSecurity>
            <underlyingSecurityTitle>
                <value>Common Stock</value>
            </underlyingSecurityTitle>
            <underlyingSecurityShares>
                <value>10000</value>
            </underlyingSecurityShares>
        </underlyingSecurity>
        <postTransactionAmounts>
            <valueOwnedFollowingTransaction>
                <value>10000</value>
            </valueOwnedFollowingTransaction>
        </postTransactionAmounts>
        <ownershipNature>
            <directOrIndirectOwnership>
                <value>D</value>
            </directOrIndirectOwnership>
        </ownershipNature>
    </derivativeSecurity>

    <footnotes>
        <footnote id="F1">Grant to reporting person of an option to buy 10,000 shares of common stock, exercisable immediately on the date of grant subject to the Issuer's right of repurchase, which right of repurchase expires on May 13, 2004, the first anniversary of the date of grant.</footnote>
    </footnotes>

    <ownerSignature>
        <signatureName>By: Wendy L. Nagy  For: L. Patrick Gage</signatureName>
        <signatureDate>2003-05-14</signatureDate>
    </ownerSignature>

</ownershipDocument>

