Chimpanzees in biomedical and behavioral research constitute a national resource that has been valuable in addressing national health needs. Facilities that house chimpanzees owned and supported by the National Institutes of Health (NIH) have successfully met the research requirements of the scientific community. The captive chimpanzee population in the United States has grown substantially, particularly over the last decade. That growth is due primarily to the success of the NIH-sponsored Chimpanzee Breeding and Research Program, which achieved the birth numbers thought necessary to meet the projected needs of biomedical research. However, the expected level of use of the chimpanzee model in biomedical research did not materialize, and that has created a complex problem that threatens both the availability of chimpanzees for research in the future and the infrastructure required to ensure the well-being of captive chimpanzees used in biomedical research. Because the present system is fragmented, it is impossible to formulate an accurate overview of the size and nature of the chimpanzee population. But, if the chimpanzee is to continue to be used in biomedical research responsibly, effectively, and cost-effectively, we must be able to oversee, track, and coordinate the maintenance and use of chimpanzees and to control the size of the population. To assess the long-range situation and to develop, implement, and monitor the application of policies for the proper use and care of chimpanzees, an authoritative, centralized oversight structure is imperative. Once it is in place, it will be possible to refine and implement this report's recommendations.