-----BEGIN PRIVACY-ENHANCED MESSAGE-----
Proc-Type: 2001,MIC-CLEAR
Originator-Name: webmaster@www.sec.gov
Originator-Key-Asymmetric:
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 TWSM7vrzLADbmYQaionwg5sDW3P6oaM5D3tdezXMm7z1T+B+twIDAQAB
MIC-Info: RSA-MD5,RSA,
 Ju+eLk3RMtDrAeaiuBLt6wZoYwcUelSHMMCzp8XoQQc2+CMqXARstH2X4Rrj2QZQ
 IsbAjLvvU6fVKnoEughRmQ==

<SEC-DOCUMENT>0001140361-09-006861.txt : 20090313
<SEC-HEADER>0001140361-09-006861.hdr.sgml : 20090313
<ACCEPTANCE-DATETIME>20090313110502
ACCESSION NUMBER:		0001140361-09-006861
CONFORMED SUBMISSION TYPE:	3
PUBLIC DOCUMENT COUNT:		1
CONFORMED PERIOD OF REPORT:	20090311
FILED AS OF DATE:		20090313
DATE AS OF CHANGE:		20090313

REPORTING-OWNER:	

	OWNER DATA:	
		COMPANY CONFORMED NAME:			Marshall Joseph W III
		CENTRAL INDEX KEY:			0001458584

	FILING VALUES:
		FORM TYPE:		3
		SEC ACT:		1934 Act
		SEC FILE NUMBER:	000-23047
		FILM NUMBER:		09678120

	BUSINESS ADDRESS:	
		BUSINESS PHONE:		267-513-1870

	MAIL ADDRESS:	
		STREET 1:		500 OFFICE CENTER DRIVE
		STREET 2:		SUITE 400
		CITY:			FT. WASHINGTON
		STATE:			PA
		ZIP:			19034

ISSUER:		

	COMPANY DATA:	
		COMPANY CONFORMED NAME:			SIGA TECHNOLOGIES INC
		CENTRAL INDEX KEY:			0001010086
		STANDARD INDUSTRIAL CLASSIFICATION:	PHARMACEUTICAL PREPARATIONS [2834]
		IRS NUMBER:				133864870
		STATE OF INCORPORATION:			DE
		FISCAL YEAR END:			1231

	BUSINESS ADDRESS:	
		STREET 1:		420 LEXINGTON AVE
		STREET 2:		SUITE 408
		CITY:			NEW YORK
		STATE:			NY
		ZIP:			10170
		BUSINESS PHONE:		2126729100

	MAIL ADDRESS:	
		STREET 1:		420 LEXINGTON AVE
		STREET 2:		SUITE 408
		CITY:			NEW YORK
		STATE:			NY
		ZIP:			10170

	FORMER COMPANY:	
		FORMER CONFORMED NAME:	SIGA PHARMACEUTICALS INC
		DATE OF NAME CHANGE:	19961108
</SEC-HEADER>
<DOCUMENT>
<TYPE>3
<SEQUENCE>1
<FILENAME>doc1.xml
<DESCRIPTION>FORM 3
<TEXT>
<XML>
<?xml version="1.0"?>
<ownershipDocument>

    <schemaVersion>X0203</schemaVersion>

    <documentType>3</documentType>

    <periodOfReport>2009-03-11</periodOfReport>

    <noSecuritiesOwned>0</noSecuritiesOwned>

    <issuer>
        <issuerCik>0001010086</issuerCik>
        <issuerName>SIGA TECHNOLOGIES INC</issuerName>
        <issuerTradingSymbol>SIGA</issuerTradingSymbol>
    </issuer>

    <reportingOwner>
        <reportingOwnerId>
            <rptOwnerCik>0001458584</rptOwnerCik>
            <rptOwnerName>Marshall Joseph W III</rptOwnerName>
        </reportingOwnerId>
        <reportingOwnerAddress>
            <rptOwnerStreet1>500 OFFICE CENTER DRIVE, SUITE 400</rptOwnerStreet1>
            <rptOwnerStreet2></rptOwnerStreet2>
            <rptOwnerCity>FT. WASHINGTON,</rptOwnerCity>
            <rptOwnerState>PA</rptOwnerState>
            <rptOwnerZipCode>19034</rptOwnerZipCode>
            <rptOwnerStateDescription></rptOwnerStateDescription>
        </reportingOwnerAddress>
        <reportingOwnerRelationship>
            <isDirector>1</isDirector>
            <isOfficer>0</isOfficer>
            <isTenPercentOwner>0</isTenPercentOwner>
            <isOther>0</isOther>
            <officerTitle></officerTitle>
            <otherText></otherText>
        </reportingOwnerRelationship>
    </reportingOwner>

    <nonDerivativeTable></nonDerivativeTable>

    <derivativeTable>
        <derivativeHolding>
            <securityTitle>
                <value>Stock Option (Right to buy)</value>
            </securityTitle>
            <conversionOrExercisePrice>
                <value>4.74</value>
            </conversionOrExercisePrice>
            <exerciseDate>
                <value>2009-03-11</value>
            </exerciseDate>
            <expirationDate>
                <value>2019-03-11</value>
            </expirationDate>
            <underlyingSecurity>
                <underlyingSecurityTitle>
                    <value>Common Stock, par value $.0001 per share</value>
                </underlyingSecurityTitle>
                <underlyingSecurityShares>
                    <value>25000</value>
                </underlyingSecurityShares>
            </underlyingSecurity>
            <ownershipNature>
                <directOrIndirectOwnership>
                    <value>D</value>
                </directOrIndirectOwnership>
            </ownershipNature>
        </derivativeHolding>
    </derivativeTable>

    <footnotes></footnotes>

    <remarks></remarks>

    <ownerSignature>
        <signatureName>/s/ Joseph W. Marshall, III</signatureName>
        <signatureDate>2009-03-11</signatureDate>
    </ownerSignature>
</ownershipDocument>
</XML>
</TEXT>
</DOCUMENT>
</SEC-DOCUMENT>
-----END PRIVACY-ENHANCED MESSAGE-----
