It has long been the aim of both the government and several professional associations to introduce increasing numbers of otherwise underrepresented minorities into the health professions. In this article, the authors evaluate the effectiveness the Robert Wood Johnson Foundation's Minority Medical Education Program (MMEP), a large, eight-site program begun in 1989 that seeks to improve the medical school acceptance rate of its participants. Data for this research are drawn from three medical school application cohorts (1992, 1996 and 1997) and analysis takes into account academic achievement, other factors such as motivation, and the characteristics of the study population. Results indicate that MMEP enhances the probability that its participants will be accepted to medical school. In the 1997 cohort, for example, the odds of acceptance were significantly higher for MMEP participants than for non-participants. The authors additionally suggest that MMEP may have an even greater effect than observed, based on the possibility that many medical school applicants participate in activities similar to MMEP. Opportunities for future research include studies of participant subgroups or specific MMEP components and assessments of MMEP mechanisms which contribute to its success.