IDEXX LABORATORIES INC /DE — Director's Dealing 2012

May 9, 2012

SEC Form 4 — Statement of Changes in Beneficial Ownership

Issuer: IDEXX LABORATORIES INC /DE (IDXX)
CIK: 0000874716
Period of Report: 2012-05-07

Reporting Person: Williams Michael J PhD (CORPORATE VICE PRESIDENT)

Non-Derivative Transactions

Date	Security	Code	Shares	Price	A/D	Holdings After	Ownership
2012-05-07	Common Stock	M	20440	$41.935	Acquired	31124	Direct
2012-05-07	Common Stock	S	24352	$88.1872	Disposed	6772	Direct

Derivative Transactions

Date	Security	Exercise Price	Code	Shares	A/D	Expiration	Underlying	Ownership
2012-05-07	Incentive Stock Option (right to buy)	$41.935	M	3758	Disposed	2014-02-13	Common Stock (3758)	Direct
2012-05-07	Non-Qualified Stock Option (right to buy)	$41.935	M	16682	Disposed	2014-02-13	Common Stock (16682)	Direct

Footnotes

F1: Includes 79 shares acquired under the IDEXX Laboratories, Inc. Employee Stock Purchase Plan on 03/30/2012.

F2: The sale price reported reflects the weighted average sale price of multiple transactions on the reported date at prices that ranged from $88.07 to $88.40, inclusive. The reporting person hereby undertakes to provide upon request to SEC staff, the issuer or a security holder of the issuer, full information regarding the number of shares sold at each separate price within the range.

F3: Grant of options to buy shares of common stock becomes exercisable as to 1,374 shares on 02/14/2011, and the remaining 2,384 shares on 02/14/2012.

F4: Grant of options to buy shares of common stock becomes exercisable as to 4,088 shares on 02/14/2008, 02/14/2009 and 02/14/2010, 2,714 shares on 02/14/2011, and the remaining 1,704 shares on 02/14/2012.