The factors influencing the career choices of medical students need to be understood so that the proportion of physicians entering primary care-defined as family practice, general internal medicine, general pediatrics, and general obstetrics and gynecology-can be increased. We sent a questionnaire to 474 University of California, San Diego (UCSD), School of Medicine alumni (classes of 1974, 1978, 1982, 1986, and 1990) inquiring about demographics, personal and medical school factors, and level of debt. A total of 351 alumni responded (74% response rate), and 327 of them were engaged in direct patient care (38% in primary care). Respondents who were older, female, an underrepresented minority, from a rural background, and who chose their specialty before medical school were significantly more likely to enter primary care. The primary care group was influenced by factors unrelated to the medical school environment, such as personal social values, whereas the top 3 factors rated by the non-primary care group were directly related to school environment. Many of the respondents in primary care reported that the environment at UCSD was antagonistic toward primary care. From 1974 to 1990, more students had debt and their total debt increased, although debt had little or no influence on specialty choice.