In 1970 approximately 81 percent of the nation's physicians were in specialty practice, and by 1990 this figure is projected to rise to 94 percent. A phenomenon of this magnitude clearly warrants intensive study. In this inquiry preference ratings for 40 specialties were obtained from 140 male and 20 female physicians and from 71 male and 18 female third-year medical students. Although significant differences were noted, there was a common hierarchy of preference observable in all four groups. For example, family and internal medicine were rated high by all four groups, whereas neurological and colon-rectal surgery were rated low; Males, and particularly male physicians, gave significantly higher ratings to surgical specialties, whereas females expressed stronger preferences for obstetrics and gynecology. Students gave lower ratings than physicians to surgical and eye, ear, nose, and throat specialties.