To determine the characteristics of physicians who move into and out of rural areas, as well as their reasons for establishing or leaving such practices, we sent questionnaires to 67 physicians who began practice in selected rural counties in upstate New York and 88 physicians who left practices in roughly the same area. From the 52 physicians (77.6 per cent) who responded to the former survey we found that 1) good professional support is mandatory for maintaining a satisfying small community practice, 2) a predisposition to small community living is essential for physicians to be recruited for rural practice, and 3) there are substantial differences with respect to demographic characteristics among persons who share similar reasons for practicing medicine in this region. For the 68 physicians (72.0) per cent ) who responded to the latter survey, the reasons for leaving could be grouped in the following categories: economic, social, and professional logistic. Although all of these factors contribute to the decision to leave, physician geographical mobility seems to stem chiefly from an unsatisfactory professional situation. These findings suggest several strategies for improving the situations in which rural physicians practice, and thus altering the massive imbalance in physician:patient ratios in urban and rural areas.