The PSIC provides the communication mechanisms needed for efficient sharing of laboratory primates by research investigators and institutions in the US. The goal is to help reduce the total number of primates needed for research, especially imported primates, by maximizing the use of existent primate resources. The PSIC's services include: 1) New Listings, a twice monthly newsletter listing current needs for and availability of primates, tissues, cadavers, equipment, and services; 2) Continuing Listings, a bi-monthly newsletter for those programs needing to advertise long term or continuing primate needs or availability; 3) Annual Resources Guide (ARG), an annual publication which lists subscribing suppliers of primates, laboratories equipment suppliers, and commercial services such as transportation and quarantine facilities; 4) referral services which immediately match telephone, facsimile, electronic mail or letter requests to open listing in the PSIC's computer database; and 5) an internet website that includes program information, the current ARG, a listing of primate taxonomy, and links to other sites of interest to the primate research community. The PSIC services research laboratories, research institutions, biotechnology and pharmaceutical companies, zoological parks, and breeding colonies. Efficient sharing of laboratory primates results in significant cost savings to the research community. Figures for 1998 alone indicate that the value of the 1,882 macaques placed through the Clearinghouse, based on the average price for a research naive, commercially supplied macaque being $1,750 in 1998, was $3.3 million. The PSIC program results in significant direct cost savings to the research community. The overall objective of the PSIC is to help maximize the use of primate resources, and to reduce the time and effort required by researchers to locate or replace animals and tissues. The benefit and necessity of such conservation efforts are increasing daily.