<SEC-DOCUMENT>0001127602-25-020747.txt : 20250820
<SEC-HEADER>0001127602-25-020747.hdr.sgml : 20250820
<ACCEPTANCE-DATETIME>20250820075844
ACCESSION NUMBER:		0001127602-25-020747
CONFORMED SUBMISSION TYPE:	3
PUBLIC DOCUMENT COUNT:		1
CONFORMED PERIOD OF REPORT:	20250819
FILED AS OF DATE:		20250820
DATE AS OF CHANGE:		20250820

REPORTING-OWNER:	

	OWNER DATA:	
		COMPANY CONFORMED NAME:			Daly James M
		CENTRAL INDEX KEY:			0001560782
		ORGANIZATION NAME:           	

	FILING VALUES:
		FORM TYPE:		3
		SEC ACT:		1934 Act
		SEC FILE NUMBER:	000-50633
		FILM NUMBER:		251233863

	MAIL ADDRESS:	
		STREET 1:		INCYTE CORPORATION EXPERIMENTAL STATION
		STREET 2:		RTE 141 & HENRY CLAY RD. BLDG E336
		CITY:			WILMINGTON
		STATE:			DE
		ZIP:			19880

ISSUER:		

	COMPANY DATA:	
		COMPANY CONFORMED NAME:			CYTOKINETICS INC
		CENTRAL INDEX KEY:			0001061983
		STANDARD INDUSTRIAL CLASSIFICATION:	PHARMACEUTICAL PREPARATIONS [2834]
		ORGANIZATION NAME:           	03 Life Sciences
		EIN:				943291317
		FISCAL YEAR END:			1231

	BUSINESS ADDRESS:	
		STREET 1:		350 OYSTER POINT BOULEVARD
		STREET 2:		.
		CITY:			SOUTH SAN FRANCISCO
		STATE:			CA
		ZIP:			94080
		BUSINESS PHONE:		(650) 624-3000

	MAIL ADDRESS:	
		STREET 1:		350 OYSTER POINT BOULEVARD
		CITY:			SOUTH SAN FRANCISCO
		STATE:			CA
		ZIP:			94080
</SEC-HEADER>
<DOCUMENT>
<TYPE>3
<SEQUENCE>1
<FILENAME>form3.xml
<DESCRIPTION>PRIMARY DOCUMENT
<TEXT>
<XML>
<?xml version="1.0"?>
<ownershipDocument>

    <schemaVersion>X0206</schemaVersion>

    <documentType>3</documentType>

    <periodOfReport>2025-08-19</periodOfReport>

    <noSecuritiesOwned>1</noSecuritiesOwned>

    <issuer>
        <issuerCik>0001061983</issuerCik>
        <issuerName>CYTOKINETICS INC</issuerName>
        <issuerTradingSymbol>CYTK</issuerTradingSymbol>
    </issuer>

    <reportingOwner>
        <reportingOwnerId>
            <rptOwnerCik>0001560782</rptOwnerCik>
            <rptOwnerName>Daly James M</rptOwnerName>
        </reportingOwnerId>
        <reportingOwnerAddress>
            <rptOwnerStreet1>350 OYSTER POINT BLVD</rptOwnerStreet1>
            <rptOwnerStreet2></rptOwnerStreet2>
            <rptOwnerCity>SOUTH SAN FRANCISCO</rptOwnerCity>
            <rptOwnerState>CA</rptOwnerState>
            <rptOwnerZipCode>94580</rptOwnerZipCode>
            <rptOwnerStateDescription></rptOwnerStateDescription>
        </reportingOwnerAddress>
        <reportingOwnerRelationship>
            <isDirector>1</isDirector>
        </reportingOwnerRelationship>
    </reportingOwner>

    <footnotes></footnotes>

    <ownerSignature>
        <signatureName>/s/ John O. Faurescu, attorney-in-fact for Mr. Daly</signatureName>
        <signatureDate>2025-08-19</signatureDate>
    </ownerSignature>
</ownershipDocument>
</XML>
</TEXT>
</DOCUMENT>
</SEC-DOCUMENT>
