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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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 JDrBDD8Jn0sxmrOEJd3e4Q==

<SEC-DOCUMENT>0001209191-08-033570.txt : 20080528
<SEC-HEADER>0001209191-08-033570.hdr.sgml : 20080528
<ACCEPTANCE-DATETIME>20080528194058
ACCESSION NUMBER:		0001209191-08-033570
CONFORMED SUBMISSION TYPE:	4
PUBLIC DOCUMENT COUNT:		1
CONFORMED PERIOD OF REPORT:	20080527
FILED AS OF DATE:		20080528
DATE AS OF CHANGE:		20080528

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

REPORTING-OWNER:	

	OWNER DATA:	
		COMPANY CONFORMED NAME:			STEIN ISAAC
		CENTRAL INDEX KEY:			0001180772

	FILING VALUES:
		FORM TYPE:		4
		SEC ACT:		1934 Act
		SEC FILE NUMBER:	000-51820
		FILM NUMBER:		08864718

	BUSINESS ADDRESS:	
		BUSINESS PHONE:		(650) 298-5300

	MAIL ADDRESS:	
		STREET 1:		515 GALVESTON DR
		CITY:			REDWOOD CITY
		STATE:			CA
		ZIP:			94063

	FORMER NAME:	
		FORMER CONFORMED NAME:	STEIN ISSAC
		DATE OF NAME CHANGE:	20020816
</SEC-HEADER>
<DOCUMENT>
<TYPE>4
<SEQUENCE>1
<FILENAME>bdn56854_bdn4is.xml
<DESCRIPTION>MAIN DOCUMENT DESCRIPTION
<TEXT>
<XML>
<?xml version="1.0"?>
<ownershipDocument>

    <schemaVersion>X0202</schemaVersion>

    <documentType>4</documentType>

    <periodOfReport>2008-05-27</periodOfReport>

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

    <reportingOwner>
        <reportingOwnerId>
            <rptOwnerCik>0001180772</rptOwnerCik>
            <rptOwnerName>STEIN ISAAC</rptOwnerName>
        </reportingOwnerId>
        <reportingOwnerAddress>
            <rptOwnerStreet1>275 MIDDLEFIELD ROAD</rptOwnerStreet1>
            <rptOwnerStreet2>STE. 1</rptOwnerStreet2>
            <rptOwnerCity>MENLO PARK</rptOwnerCity>
            <rptOwnerState>CA</rptOwnerState>
            <rptOwnerZipCode>94025</rptOwnerZipCode>
            <rptOwnerStateDescription></rptOwnerStateDescription>
        </reportingOwnerAddress>
        <reportingOwnerRelationship>
            <isDirector>1</isDirector>
            <isOfficer>0</isOfficer>
            <isTenPercentOwner>0</isTenPercentOwner>
            <isOther>0</isOther>
        </reportingOwnerRelationship>
    </reportingOwner>

    <nonDerivativeTable></nonDerivativeTable>

    <derivativeTable>
        <derivativeTransaction>
            <securityTitle>
                <value>Stock Option (right to buy)</value>
            </securityTitle>
            <conversionOrExercisePrice>
                <value>5.33</value>
            </conversionOrExercisePrice>
            <transactionDate>
                <value>2008-05-27</value>
            </transactionDate>
            <transactionCoding>
                <transactionFormType>4</transactionFormType>
                <transactionCode>A</transactionCode>
                <equitySwapInvolved>0</equitySwapInvolved>
            </transactionCoding>
            <transactionAmounts>
                <transactionShares>
                    <value>6250</value>
                </transactionShares>
                <transactionPricePerShare>
                    <value>0</value>
                </transactionPricePerShare>
                <transactionAcquiredDisposedCode>
                    <value>A</value>
                </transactionAcquiredDisposedCode>
            </transactionAmounts>
            <exerciseDate>
                <value>2008-06-27</value>
                <footnoteId id="F1"/>
            </exerciseDate>
            <expirationDate>
                <value>2018-05-27</value>
            </expirationDate>
            <underlyingSecurity>
                <underlyingSecurityTitle>
                    <value>Common Stock</value>
                </underlyingSecurityTitle>
                <underlyingSecurityShares>
                    <value>6250</value>
                </underlyingSecurityShares>
            </underlyingSecurity>
            <postTransactionAmounts>
                <sharesOwnedFollowingTransaction>
                    <value>6250</value>
                </sharesOwnedFollowingTransaction>
            </postTransactionAmounts>
            <ownershipNature>
                <directOrIndirectOwnership>
                    <value>D</value>
                </directOrIndirectOwnership>
            </ownershipNature>
        </derivativeTransaction>
    </derivativeTable>

    <footnotes>
        <footnote id="F1">Automatic grant to Reporting Person of a non-statutory stock option.  1/48th of the shares vest monthly from the date of grant over four years. The option expires ten years after the date of grant, unless it expires sooner pursuant to the terms of the Company's 2005 Non-Employee Directors' Stock Option Plan.</footnote>
    </footnotes>

    <ownerSignature>
        <signatureName>/s/ Brent D. Fassett, Attorney-in-Fact</signatureName>
        <signatureDate>2008-05-28</signatureDate>
    </ownerSignature>
</ownershipDocument>
</XML>
</TEXT>
</DOCUMENT>
</SEC-DOCUMENT>
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