-----BEGIN PRIVACY-ENHANCED MESSAGE-----
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>0001209191-09-059074.txt : 20091230
<SEC-HEADER>0001209191-09-059074.hdr.sgml : 20091230
<ACCEPTANCE-DATETIME>20091230162712
ACCESSION NUMBER:		0001209191-09-059074
CONFORMED SUBMISSION TYPE:	4
PUBLIC DOCUMENT COUNT:		1
CONFORMED PERIOD OF REPORT:	20091228
FILED AS OF DATE:		20091230
DATE AS OF CHANGE:		20091230

REPORTING-OWNER:	

	OWNER DATA:	
		COMPANY CONFORMED NAME:			Simms Michael J
		CENTRAL INDEX KEY:			0001427117

	FILING VALUES:
		FORM TYPE:		4
		SEC ACT:		1934 Act
		SEC FILE NUMBER:	000-51820
		FILM NUMBER:		091266739

	MAIL ADDRESS:	
		STREET 1:		2091 STIERLIN COURT
		CITY:			MOUNTAIN VIEW
		STATE:			CA
		ZIP:			94043

ISSUER:		

	COMPANY DATA:	
		COMPANY CONFORMED NAME:			Alexza Pharmaceuticals Inc.
		CENTRAL INDEX KEY:			0001344413
		STANDARD INDUSTRIAL CLASSIFICATION:	PHARMACEUTICAL PREPARATIONS [2834]
		IRS NUMBER:				770567768
		STATE OF INCORPORATION:			DE
		FISCAL YEAR END:			1231

	BUSINESS ADDRESS:	
		STREET 1:		2091 STIERLIN COURT
		CITY:			MOUNTAIN VIEW
		STATE:			CA
		ZIP:			94043
		BUSINESS PHONE:		650.944.7000

	MAIL ADDRESS:	
		STREET 1:		2091 STIERLIN COURT
		CITY:			MOUNTAIN VIEW
		STATE:			CA
		ZIP:			94043
</SEC-HEADER>
<DOCUMENT>
<TYPE>4
<SEQUENCE>1
<FILENAME>c94192_4x0.xml
<DESCRIPTION>MAIN DOCUMENT DESCRIPTION
<TEXT>
<XML>
<?xml version="1.0"?>
<ownershipDocument>

    <schemaVersion>X0303</schemaVersion>

    <documentType>4</documentType>

    <periodOfReport>2009-12-28</periodOfReport>

    <issuer>
        <issuerCik>0001344413</issuerCik>
        <issuerName>Alexza Pharmaceuticals Inc.</issuerName>
        <issuerTradingSymbol>ALXA</issuerTradingSymbol>
    </issuer>

    <reportingOwner>
        <reportingOwnerId>
            <rptOwnerCik>0001427117</rptOwnerCik>
            <rptOwnerName>Simms Michael J</rptOwnerName>
        </reportingOwnerId>
        <reportingOwnerAddress>
            <rptOwnerStreet1>ALEXZA PHARMACEUTICALS INC.</rptOwnerStreet1>
            <rptOwnerStreet2>2091 STIERLIN COURT</rptOwnerStreet2>
            <rptOwnerCity>MOUNTAIN VIEW</rptOwnerCity>
            <rptOwnerState>CA</rptOwnerState>
            <rptOwnerZipCode>94043</rptOwnerZipCode>
            <rptOwnerStateDescription></rptOwnerStateDescription>
        </reportingOwnerAddress>
        <reportingOwnerRelationship>
            <isDirector>0</isDirector>
            <isOfficer>1</isOfficer>
            <isTenPercentOwner>0</isTenPercentOwner>
            <isOther>0</isOther>
            <officerTitle>SVP, Operations &amp; Quality</officerTitle>
        </reportingOwnerRelationship>
    </reportingOwner>

    <nonDerivativeTable></nonDerivativeTable>

    <derivativeTable>
        <derivativeTransaction>
            <securityTitle>
                <value>Stock Option (right to buy)</value>
            </securityTitle>
            <conversionOrExercisePrice>
                <value>2.37</value>
            </conversionOrExercisePrice>
            <transactionDate>
                <value>2009-12-28</value>
            </transactionDate>
            <deemedExecutionDate>
                <value>2009-12-28</value>
            </deemedExecutionDate>
            <transactionCoding>
                <transactionFormType>4</transactionFormType>
                <transactionCode>A</transactionCode>
                <equitySwapInvolved>0</equitySwapInvolved>
            </transactionCoding>
            <transactionAmounts>
                <transactionShares>
                    <value>49626</value>
                </transactionShares>
                <transactionPricePerShare>
                    <value>0</value>
                </transactionPricePerShare>
                <transactionAcquiredDisposedCode>
                    <value>A</value>
                </transactionAcquiredDisposedCode>
            </transactionAmounts>
            <exerciseDate>
                <footnoteId id="F1"/>
            </exerciseDate>
            <expirationDate>
                <value>2019-12-27</value>
            </expirationDate>
            <underlyingSecurity>
                <underlyingSecurityTitle>
                    <value>Common Stock</value>
                </underlyingSecurityTitle>
                <underlyingSecurityShares>
                    <value>49626</value>
                </underlyingSecurityShares>
            </underlyingSecurity>
            <postTransactionAmounts>
                <sharesOwnedFollowingTransaction>
                    <value>49626</value>
                </sharesOwnedFollowingTransaction>
            </postTransactionAmounts>
            <ownershipNature>
                <directOrIndirectOwnership>
                    <value>D</value>
                </directOrIndirectOwnership>
            </ownershipNature>
        </derivativeTransaction>
    </derivativeTable>

    <footnotes>
        <footnote id="F1">Grant pursuant to the terms of the Issuer's 2009-2010 Performance Based Incentive Program (the &quot;Performance Program&quot;) to Reporting Person of a stock option under the Issuer's 2005 Equity Incentive Plan (the &quot;Plan&quot;).  50% of such shares vest upon the Issuer's achievement of the approval of the New Drug Application (the &quot;NDA&quot;) for the Issuer's AZ-004 (Staccato loxapine) product candidate (the &quot;Second Milestone&quot;), with the remaining 50% of such shares vesting upon the first anniversary of the achievement of the Second Milestone, provided that at the relevant vesting date the Reporting Person's continuous service to the Issuer has not been terminated as defined in or as determined under the Plan and the Reporting Person has at least a minimum personal performance rating of 70% under the Performance Program.  The option expires ten years after the date of grant.</footnote>
    </footnotes>

    <ownerSignature>
        <signatureName>/s/ Brent D. Fassett, Attorney-in-Fact</signatureName>
        <signatureDate>2009-12-30</signatureDate>
    </ownerSignature>
</ownershipDocument>
</XML>
</TEXT>
</DOCUMENT>
</SEC-DOCUMENT>
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