Investor Relations

WILMINGTON, Mass.--(BUSINESS WIRE)--April 1, 2004--Charles River Laboratories International, Inc. (NYSE:CRL) will release first-quarter financial results on Wednesday, April 28, 2004, after the market closes. A conference call has been scheduled to discuss the results on Thursday, April 29, 2004, at 8:30 a.m. Eastern Daylight Time.

Investors will have the opportunity to listen to a live webcast of the conference call through the Investor Relations section of the Company's website at ir.criver.com. A replay will be accessible through the website approximately two hours following the conference call and will remain available until Thursday, May 6, 2004.

Charles River Laboratories, based in Wilmington, Massachusetts, is a leading provider of critical research tools and integrated support services that enable innovative and efficient drug discovery and development. The Company is the global leader in providing the animal research models required in research and development for new drugs, devices and therapies. The Company also offers a broad and growing portfolio of products and services that enable customers to reduce cost, increase speed, and enhance productivity and effectiveness in drug discovery and development. Charles River's customer base spans over 50 countries, and includes all of the major pharmaceutical companies, biotechnology companies, and many leading hospitals and academic institutions. For more information, visit the Company's web site at www.criver.com.

CONTACT: Charles River Laboratories International, Inc.
Investor Relations:
Susan E. Hardy, 978-658-6000 Ext. 1616

SOURCE: Charles River Laboratories International, Inc.