A study of the characteristics of rural counties that gained or failed to gain young physicians examined location choices of all physicians who graduated from allopathic and osteopathic schools of medicine between 1974 and 1978 and were practicing in a primary care specialty in 2,111 rural counties in 1983. First, the characteristics of counties in which young physicians were located were compared with the characteristics of counties that failed to attract young physicians and significant differences were identified. The 1,228 gaining counties tended to have more population, higher population growth rates, greater population density, a better educated population, higher income, less agriculture, and more health resources than the 883 counties that did not gain a physician. The findings suggest that there are differences between the counties selected by National Health Service Corps (NHSC) alumni and non-alumni and that, for NHSC alumni particularly, factors other that the characteristics of communities appear to intervene in the location decision. It seems likely that the NHSC service itself is one of those intervening variables. This is suggested by the fact that satisfaction with aspects of the NHSC experience is positively associated with a decision to choose rural and Health Manpower Shortage Area practice. Numerous data tables supplement the text. (JHZ)