Between 1973 and 1983, the number of foreign nationals from developing nations who entered the United States for graduate medical education decreased by approximately 90%. Many of those who would have studied in the United States if this decrease had not occurred would have returned home to serve their countries. To estimate the impact of this loss, a survey was conducted in six major cities in Latin America between 1983 and 1989. Selected local medical students interviewed 554 physicians who had returned home after U.S. trai ing and 60 of their classmates who had not trained there. The findings indicate that the returned physicians had given approximately twice as much time to teaching, research, and medical administration as did those who had not left home. The authors maintain that this and related findings show how the curtailment of opportunities for training foreign nationals in the United States is detrimental to both the aspirations of developing nations and the influence of the United States in world affairs. © 1991 Association of American Medical Colleges.