<SUBMISSION>
<ACCESSION-NUMBER>0000874716-03-000089
<TYPE>S-8 POS
<PUBLIC-DOCUMENT-COUNT>1
<FILING-DATE>20030918
<EFFECTIVENESS-DATE>20030918
<FILER>
<COMPANY-DATA>
<CONFORMED-NAME>IDEXX LABORATORIES INC /DE
<CIK>0000874716
<ASSIGNED-SIC>2835
<IRS-NUMBER>010393723
<STATE-OF-INCORPORATION>DE
<FISCAL-YEAR-END>1231
</COMPANY-DATA>
<FILING-VALUES>
<FORM-TYPE>S-8 POS
<ACT>33
<FILE-NUMBER>333-11201
<FILM-NUMBER>03901177
</FILING-VALUES>
<BUSINESS-ADDRESS>
<STREET1>ONE IDEXX DRIVE
<CITY>WESTBROOK
<STATE>ME
<ZIP>04092-2041
<PHONE>2078560300
</BUSINESS-ADDRESS>
<MAIL-ADDRESS>
<STREET1>ONE IDEXX DRIVE
<CITY>WESTBROOK
<STATE>ME
<ZIP>04092-2041
</MAIL-ADDRESS>
<FORMER-COMPANY>
<FORMER-CONFORMED-NAME>IDEXX CORP / DE
<DATE-CHANGED>19600201
</FORMER-COMPANY>
</FILER>
<DOCUMENT>
<TYPE>S-8 POS
<SEQUENCE>1
<FILENAME>pos1s8_1991sop.htm
<DESCRIPTION>POS NO. 1 TO S-8 1991 STOCK OPTION PLAN
<TEXT>
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<TITLE>POS No. 1 S-8 (1991 SOP)</TITLE>
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<P ALIGN=RIGHT><FONT FACE="Times New Roman, Times, Serif" SIZE=2>As Filed with the
Securities and Exchange Commission on September 18, 2003, Registration No.&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;<BR>
Registration No. 333-11201 on August 30, 1996<BR>Registration No. 33-95616 on August 9, 1995
<BR>Registration No. 33-64204 on June 10, 1993<BR>Registration No. 33-48404 on June 8, 1992<BR>
Registration No. 33-42845 on September 18, 1991</FONT></P>

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<H1 ALIGN=CENTER><FONT FACE="Times New Roman, Times, Serif" SIZE=2>SECURITIES AND
EXCHANGE COMMISSION<BR>WASHINGTON, DC 20549  </FONT></H1>

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<H1 ALIGN=CENTER><FONT FACE="Times New Roman, Times, Serif" SIZE=2>POST-EFFECTIVE AMENDMENT NO. 1<BR>TO<BR>FORM S-8 </FONT></H1>

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<H1 ALIGN=CENTER><FONT FACE="Times New Roman, Times, Serif" SIZE=2>REGISTRATION STATEMENT
UNDER<BR>THE SECURITIES ACT OF 1933 </FONT></H1>

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<P ALIGN=CENTER><FONT FACE="Times New Roman, Times, Serif" SIZE="2"><B>IDEXX LABORATORIES, INC.</B><BR>(Exact name of
registrant as specified in its charter) </FONT> </P>

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     <TH COLSPAN=2><FONT FACE="Times New Roman, Times, Serif" SIZE=2>Delaware</FONT></TH>
     <TH COLSPAN=2><FONT FACE="Times New Roman, Times, Serif" SIZE=2>01-0393723</FONT></TH></TR>
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     <TD WIDTH=49% ALIGN=CENTER><FONT FACE="Times New Roman, Times, Serif" SIZE="1">(State or other jurisdiction of incorporation or organization)<BR> </FONT></TD>
     <TD WIDTH=14% ALIGN=LEFT><FONT FACE="Times New Roman, Times, Serif" SIZE=2>&nbsp;</FONT></TD>
     <TD WIDTH=49% ALIGN=CENTER><FONT FACE="Times New Roman, Times, Serif" SIZE="1">(I.R.S. Employer Identification No.)<BR></FONT></TD>
     <TD WIDTH=2% ALIGN=LEFT><FONT FACE="Times New Roman, Times, Serif" SIZE=2>&nbsp;</FONT></TD></TR>
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     <TD ALIGN=CENTER><FONT FACE="Times New Roman, Times, Serif" SIZE="2"><B>One IDEXX Drive, Westbrook, Maine</B> </FONT></TD><TD ALIGN=LEFT><FONT FACE="Times New Roman, Times, Serif" SIZE=2>&nbsp;</FONT></TD>
     <TD ALIGN=CENTER><FONT FACE="Times New Roman, Times, Serif" SIZE="2"><B>04092</B> </FONT></TD><TD ALIGN=LEFT><FONT FACE="Times New Roman, Times, Serif" SIZE=2>&nbsp;</FONT></TD></TR>
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     <TD ALIGN=CENTER><FONT FACE="Times New Roman, Times, Serif" SIZE="1">(Address of principal executive offices)</FONT></TD><TD ALIGN=LEFT><FONT FACE="Times New Roman, Times, Serif" SIZE=2>&nbsp;</FONT></TD>
     <TD ALIGN=CENTER><FONT FACE="Times New Roman, Times, Serif" SIZE="1">(Zip Code)</FONT></TD><TD ALIGN=LEFT><FONT FACE="Times New Roman, Times, Serif" SIZE=2>&nbsp;</FONT></TD></TR>
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     <TD ALIGN=CENTER><FONT FACE="Times New Roman, Times, Serif" SIZE=2></FONT></TD><TD ALIGN=LEFT><FONT FACE="Times New Roman, Times, Serif" SIZE=2>&nbsp;</FONT></TD></TR>
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<P ALIGN=CENTER><FONT FACE="Times New Roman, Times, Serif" SIZE="2"><B>1991 STOCK OPTION
PLAN </B><BR>(Full Title of the Plan) </FONT> </P>

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<P ALIGN=CENTER><FONT FACE="Times New Roman, Times, Serif" SIZE="2"><B>Conan R. Deady, Esq.<BR>General
Counsel<BR>IDEXX Laboratories, Inc.<BR>One IDEXX Drive, Westbrook, Maine 04092</B><BR>(Name and Address of Agent For Service)</FONT> </P>

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<P ALIGN=CENTER><FONT FACE="Times New Roman, Times, Serif" SIZE="2"><B>(207) 856-0300</B><BR>(Telephone number, including Area Code,
of Agent for Service) </FONT></P>



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<P><FONT FACE="Times New Roman, Times, Serif" SIZE=2>&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;Pursuant
to registration statements on Form S-8 (the &#147;1991 Plan Registration Statements&#148;)
filed with the Commission on September 18, 1991 (File No. 33-42845), June 8, 1992 (File
No. 33-48404), June 10, 1993 (File No. 33-64204), August 9, 1995 (File No. 33-95616) and
August 30, 1996 (File No. 333-11201), the Registrant registered 6,475,000 shares of Common
Stock, $.10 par value per share of IDEXX Laboratories, Inc. (the &#147;Company&#148;)
(giving effect to stock splits effected in the form of stock dividends subsequent to the
filing of June 10, 1993 registration statement) in connection with the Company&#146;s 1991
Stock Option Plan (&#147;1991 Plan&#148;). The 1991 Plan Registration Statements covered
shares of Common Stock issuable upon the exercise of options granted under the 1991 Plan.
As of May 21, 2003, an aggregate of 8,574 shares of Common Stock covered by the 1991 Plan
Registration Statements had not previously been issued or were not subject to outstanding
stock options (the &#147;Unused 1991 Shares&#148;). </FONT></P>

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<P><FONT FACE="Times New Roman, Times, Serif" SIZE=2>&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;This
Post-Effective Amendment No. 1 to the 1991 Plan Registration Statements is being filed for
the purpose of transferring the Unused 1991 Shares to a new registration statement on Form
S-8 registering 1,850,000 shares of Common Stock issuable pursuant to stock based awards
to be issued under the Company&#146;s 2003 Stock Incentive Plan. </FONT></P>
<BR>
<BR>
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<A NAME=A002></A>
<H1 ALIGN=CENTER><FONT FACE="Times New Roman, Times, Serif" SIZE=2>SIGNATURES </FONT></H1>

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<P><FONT FACE="Times New Roman, Times, Serif" SIZE=2>&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;Pursuant
to Rule 478 under the Securities Act, the Registrant has duly caused this Post-Effective
Amendment No. 1 to the Registration Statement to be signed on its behalf by the
undersigned, thereunto duly authorized, in the City of Westbrook, State of Maine on this
18th day of September, 2003. </FONT></P>

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     <TD WIDTH="50%"><FONT SIZE="2"></FONT></TD>
     <TD WIDTH="50%"><FONT SIZE="2"><B>IDEXX LABORATORIES, INC.</B> </FONT></TD></TR>
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     <TD><FONT SIZE="1">&nbsp;&nbsp;&nbsp;&nbsp;</FONT></TD>
     <TD><FONT SIZE="1">&nbsp;&nbsp;&nbsp;&nbsp;</FONT></TD></TR>
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     <TD><FONT SIZE="2"></FONT></TD>
     <TD><FONT SIZE="2">By: /s/ Conan R. Deady</FONT><HR WIDTH=100% SIZE=1 COLOR=BLACK NOSHADE></TD></TR>
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     <TD><FONT SIZE="2"></FONT></TD>
     <TD><FONT SIZE="2">Conan R. Deady<BR>
Vice President, General Counsel and<BR>Secretary</FONT></TD></TR>
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</SUBMISSION>
