<SEC-DOCUMENT>0001140361-11-040086.txt : 20110808
<SEC-HEADER>0001140361-11-040086.hdr.sgml : 20110808
<ACCEPTANCE-DATETIME>20110808070423
ACCESSION NUMBER:		0001140361-11-040086
CONFORMED SUBMISSION TYPE:	4
PUBLIC DOCUMENT COUNT:		1
CONFORMED PERIOD OF REPORT:	20110804
FILED AS OF DATE:		20110808
DATE AS OF CHANGE:		20110808

REPORTING-OWNER:	

	OWNER DATA:	
		COMPANY CONFORMED NAME:			SAVAS PAUL G
		CENTRAL INDEX KEY:			0001275756

	FILING VALUES:
		FORM TYPE:		4
		SEC ACT:		1934 Act
		SEC FILE NUMBER:	000-23047
		FILM NUMBER:		111015634

	MAIL ADDRESS:	
		STREET 1:		35 EAST 62ND STREET
		CITY:			NEW YORK
		STATE:			NY
		ZIP:			10021

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:		35 EAST 62ND STREET
		CITY:			NEW YORK
		STATE:			NY
		ZIP:			10065
		BUSINESS PHONE:		212-672-9100

	MAIL ADDRESS:	
		STREET 1:		35 EAST 62ND STREET
		CITY:			NEW YORK
		STATE:			NY
		ZIP:			10065

	FORMER COMPANY:	
		FORMER CONFORMED NAME:	SIGA PHARMACEUTICALS INC
		DATE OF NAME CHANGE:	19961108
</SEC-HEADER>
<DOCUMENT>
<TYPE>4
<SEQUENCE>1
<FILENAME>doc1.xml
<DESCRIPTION>FORM 4
<TEXT>
<XML>
<?xml version="1.0"?>
<ownershipDocument>

    <schemaVersion>X0304</schemaVersion>

    <documentType>4</documentType>

    <periodOfReport>2011-08-04</periodOfReport>

    <notSubjectToSection16>0</notSubjectToSection16>

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

    <reportingOwner>
        <reportingOwnerId>
            <rptOwnerCik>0001275756</rptOwnerCik>
            <rptOwnerName>SAVAS PAUL G</rptOwnerName>
        </reportingOwnerId>
        <reportingOwnerAddress>
            <rptOwnerStreet1>C/O SIGA TECHNOLOGIES, INC.</rptOwnerStreet1>
            <rptOwnerStreet2>35 EAST 62ND STREET</rptOwnerStreet2>
            <rptOwnerCity>NEW YORK</rptOwnerCity>
            <rptOwnerState>NY</rptOwnerState>
            <rptOwnerZipCode>10065</rptOwnerZipCode>
            <rptOwnerStateDescription></rptOwnerStateDescription>
        </reportingOwnerAddress>
        <reportingOwnerRelationship>
            <isDirector>1</isDirector>
            <isOfficer>0</isOfficer>
            <isTenPercentOwner>0</isTenPercentOwner>
            <isOther>0</isOther>
            <officerTitle></officerTitle>
            <otherText></otherText>
        </reportingOwnerRelationship>
    </reportingOwner>

    <nonDerivativeTable>
        <nonDerivativeTransaction>
            <securityTitle>
                <value>Common Stock, par value $.0001 per share</value>
            </securityTitle>
            <transactionDate>
                <value>2011-08-04</value>
            </transactionDate>
            <deemedExecutionDate></deemedExecutionDate>
            <transactionCoding>
                <transactionFormType>4</transactionFormType>
                <transactionCode>P</transactionCode>
                <equitySwapInvolved>0</equitySwapInvolved>
            </transactionCoding>
            <transactionAmounts>
                <transactionShares>
                    <value>10000</value>
                </transactionShares>
                <transactionPricePerShare>
                    <value>6.29</value>
                    <footnoteId id="F1"/>
                </transactionPricePerShare>
                <transactionAcquiredDisposedCode>
                    <value>A</value>
                </transactionAcquiredDisposedCode>
            </transactionAmounts>
            <postTransactionAmounts>
                <sharesOwnedFollowingTransaction>
                    <value>46840</value>
                </sharesOwnedFollowingTransaction>
            </postTransactionAmounts>
            <ownershipNature>
                <directOrIndirectOwnership>
                    <value>D</value>
                </directOrIndirectOwnership>
            </ownershipNature>
        </nonDerivativeTransaction>
    </nonDerivativeTable>

    <derivativeTable></derivativeTable>

    <footnotes>
        <footnote id="F1">The price reported in Column 4 is a weighted average price.  These shares were sold in multiple transactions at prices ranging from $6.26 to $6.30, inclusive.  The reporting person undertakes to provide to SIGA Technologies, Inc. (the &quot;Issuer&quot;), any security holder of the Issuer, or the staff of the Securities and Exchange Commission, upon request, full information regarding the number of shares sold at each separate price within the ranges set forth in this footnote.</footnote>
    </footnotes>

    <remarks></remarks>

    <ownerSignature>
        <signatureName>/s/ Paul G. Savas</signatureName>
        <signatureDate>2011-08-08</signatureDate>
    </ownerSignature>
</ownershipDocument>
</XML>
</TEXT>
</DOCUMENT>
</SEC-DOCUMENT>
