The recent growth in domestic physician supply prompted an investigation of international trends. Using data from the World Health Organization, it was determined that the number of physicians in the world grew from 4.8 per 10,000 population to 10.1 per 10,000 during the period 1950 through 1979. There was a 96% increase in industrialized nations, 223% in nations with centrally planned economies, 164% in middle-income nations, and 29% in low-income nations. Relationships in growth in physician supply and production of medical graduates are discussed. Implications of the inequities between the various groupings of countries are discussed. (JAMA1985;253:3129-3132)