The authors studied the physical fitness of first-year students attending an osteopathic medical college between 1981 and 1986. Overall, 319 (49.2%) of all students entering during this period participated in a comprehensive health and fitness assessment. The mean treadmill performance times for men and women were 20.4 minutes and 15.5 minutes, respectively, using a modified Balke protocol. Men and women were at the 72nd and 79th percentiles, respectively, for physical fitness. In multivariate regression models that adjusted for confounding variables, body fat percentage was a highly significant negative predictor of fitness in both men and women. Forced vital capacity was also a highly significant predictor in women. The results of the study suggest that the fitness of medical students can be improved by implementing health promotion measures that encourage regular physical activity and dietary modification. A greater emphasis on health promotion in the medical curriculum may help students to adopt more healthy behaviors and, in addition, encourage them to provide preventive medical counseling to their patients.