In 1969 over 2300 foreign medical school graduates obtained a license to practice in the United States. In 1968, 15,582 interns and residents among the 47,494 in U.S. hospitals were foreign educated. The flow of foreign physicians to the United States has escalated dramatically in recent years, and today more come from the underdeveloped countries than ever before. This paper probes reasons for the influx, providing detailed statistical backup such as income differentials and other factors affecting migration. Among the conclusions: Prospects for developing nations look dim, as the lure of more money plus an emphasis here and abroad on specialized training exercises its influence to siphon off needed physicians. But, with respect to medical trainees, the situation may not be as bad as it looks: The United States receives the physician's services for a number of years, and his home country eventually receives a more highly trained doctor. 118 pp. Ref.