US/Japan meetings on laboratory animal science have been held virtually every year since 1980 under the US/Japan Cooperative Program on Science and Technology. Over the years these meetings have resulted in a number of important documents including the Manual of Microbiologic Monitoring of Laboratory Animals published in 1994 and the article Establishment and Preservation of Reference Inbred Strains of Rats for General Purposes. In addition to these publications, the meetings have been instrumental in increasing awareness of the need for microbiologic monitoring of laboratory rodents and the need for genetic definition and monitoring of mice and rats. In cooperation with the Comparative Medicine section of NCRR/NIH, the ILAR Council and staff are pleased to become the host for this important annual meeting and look forward to participating in future meetings. The support and sponsorship of NCRR (P40 RR 11611) in the United States and the Central Institute for Experimental Animals in Japan are gratefully acknowledged. Bringing together the leading scientists in the field of laboratory animal care has resulted in increased understanding of American and Japanese approaches to laboratory animal science and should continue to strengthen efforts to harmonize approaches aimed at resolving common challenges in the use of animal models for biomedical research and testing. This effort to improve understanding and cooperation between Japan and the United States should also be useful in developing similar interaction with other regions of the world including Europe, Australia, and Southeast Asia.