The National Library of Medicine (NLM) has a broad mission in biomedical information service. There are three major reasons for NLM, as a national institution, having an international program: first, the global nature of disease; second, the international scope of medical literature; and third, the universal goal of better communication. This paper reviews NLM's programs in relation to international medical information exchange: International MEDLARS Centers, collaboration with WHO and PAHO, NLM Special Foreign Currency Program, and development of the NLM collection.