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Proc-Type: 2001,MIC-CLEAR
Originator-Name: webmaster@www.sec.gov
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MIC-Info: RSA-MD5,RSA,
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<SEC-DOCUMENT>0001472157-10-000001.txt : 20100528
<SEC-HEADER>0001472157-10-000001.hdr.sgml : 20100528
<ACCEPTANCE-DATETIME>20100528171516
ACCESSION NUMBER:		0001472157-10-000001
CONFORMED SUBMISSION TYPE:	4
PUBLIC DOCUMENT COUNT:		1
CONFORMED PERIOD OF REPORT:	20100528
FILED AS OF DATE:		20100528
DATE AS OF CHANGE:		20100528

ISSUER:		

	COMPANY DATA:	
		COMPANY CONFORMED NAME:			OMEROS CORP
		CENTRAL INDEX KEY:			0001285819
		STANDARD INDUSTRIAL CLASSIFICATION:	PHARMACEUTICAL PREPARATIONS [2834]
		IRS NUMBER:				000000000

	BUSINESS ADDRESS:	
		STREET 1:		1420 5TH AVE
		STREET 2:		SUITE 2600
		CITY:			SEATTLE
		STATE:			WA
		ZIP:			98101
		BUSINESS PHONE:		206-623-4688

REPORTING-OWNER:	

	OWNER DATA:	
		COMPANY CONFORMED NAME:			Aspiri Ray
		CENTRAL INDEX KEY:			0001472157

	FILING VALUES:
		FORM TYPE:		4
		SEC ACT:		1934 Act
		SEC FILE NUMBER:	001-34475
		FILM NUMBER:		10867443

	MAIL ADDRESS:	
		STREET 1:		1420 FIFTH AVENUE
		STREET 2:		SUITE 2600
		CITY:			SEATTLE
		STATE:			WA
		ZIP:			98101-2347
</SEC-HEADER>
<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>2010-05-28</periodOfReport>

    <notSubjectToSection16>0</notSubjectToSection16>

    <issuer>
        <issuerCik>0001285819</issuerCik>
        <issuerName>OMEROS CORP</issuerName>
        <issuerTradingSymbol>OMER</issuerTradingSymbol>
    </issuer>

    <reportingOwner>
        <reportingOwnerId>
            <rptOwnerCik>0001472157</rptOwnerCik>
            <rptOwnerName>Aspiri Ray</rptOwnerName>
        </reportingOwnerId>
        <reportingOwnerAddress>
            <rptOwnerStreet1>1420 FIFTH AVENUE</rptOwnerStreet1>
            <rptOwnerStreet2>SUITE 2600</rptOwnerStreet2>
            <rptOwnerCity>SEATTLE</rptOwnerCity>
            <rptOwnerState>WA</rptOwnerState>
            <rptOwnerZipCode>98101-2347</rptOwnerZipCode>
            <rptOwnerStateDescription></rptOwnerStateDescription>
        </reportingOwnerAddress>
        <reportingOwnerRelationship>
            <isDirector>1</isDirector>
            <isOfficer>0</isOfficer>
            <isTenPercentOwner>0</isTenPercentOwner>
            <isOther>0</isOther>
        </reportingOwnerRelationship>
    </reportingOwner>

    <derivativeTable>
        <derivativeTransaction>
            <securityTitle>
                <value>Stock Option (Right to Buy)</value>
            </securityTitle>
            <conversionOrExercisePrice>
                <value>5.92</value>
            </conversionOrExercisePrice>
            <transactionDate>
                <value>2010-05-28</value>
            </transactionDate>
            <transactionCoding>
                <transactionFormType>4</transactionFormType>
                <transactionCode>A</transactionCode>
                <equitySwapInvolved>0</equitySwapInvolved>
            </transactionCoding>
            <transactionTimeliness>
                <value></value>
            </transactionTimeliness>
            <transactionAmounts>
                <transactionShares>
                    <value>5000</value>
                </transactionShares>
                <transactionPricePerShare>
                    <value>0</value>
                </transactionPricePerShare>
                <transactionAcquiredDisposedCode>
                    <value>A</value>
                </transactionAcquiredDisposedCode>
            </transactionAmounts>
            <exerciseDate>
                <footnoteId id="F1"/>
            </exerciseDate>
            <expirationDate>
                <value>2020-05-27</value>
            </expirationDate>
            <underlyingSecurity>
                <underlyingSecurityTitle>
                    <value>Common Stock</value>
                </underlyingSecurityTitle>
                <underlyingSecurityShares>
                    <value>5000</value>
                </underlyingSecurityShares>
            </underlyingSecurity>
            <postTransactionAmounts>
                <sharesOwnedFollowingTransaction>
                    <value>5000</value>
                </sharesOwnedFollowingTransaction>
            </postTransactionAmounts>
            <ownershipNature>
                <directOrIndirectOwnership>
                    <value>D</value>
                </directOrIndirectOwnership>
            </ownershipNature>
        </derivativeTransaction>
    </derivativeTable>

    <footnotes>
        <footnote id="F1">This Option shall fully vest and become exercisable on the date that is immediately prior to the day of the next annual meeting of the shareholders of the Company held after the Date of Grant of this Option, provided that the Participant continues to serve as a director of the Company through such date.</footnote>
    </footnotes>

    <ownerSignature>
        <signatureName>/s/ Alex F. Sutter, attorney-in-fact on behalf of Ray Aspiri</signatureName>
        <signatureDate>2010-05-28</signatureDate>
    </ownerSignature>
</ownershipDocument>
</XML>
</TEXT>
</DOCUMENT>
</SEC-DOCUMENT>
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