Since the 1960s a number of physicians have completed both their baccalaureate and their M.D. degrees in six or fewer years. In this longitudinal study the authors track the academic performances, clinical ratings, and career follow-up data of 659 students in one of these accelerated programs, the Jefferson Medical College-Pennsylvania State University B.S.-M.D. program, from entering years 1964 through 1989. The medical school performances, clinical performances in residencies, and rates of board certification and faculty appointment of the accelerated students compared favorably with those of a control group of medical students with similar high school credentials who had followed a four-year baccalaureate program. The authors conclude that a carefully chosen group of students can achieve high academic standards in an accelerated medical school program, graduate as younger physicians able to perform well in postgraduate training, and go on to highly productive careers in medicine.