A study was conducted to predict performance of majority and minority students in medical school by analyzing results of the National Board of Medical Examiners (NBME), Parts I and II. Data were collected from members of the 1975 and 1976 graduating classes of nine medical schools, and included Medical College Admission Test (MCAT) scores, undergraduate grade point averages (GPA), undergraduate school attended, sex, race, and medical school characteristics. Race was coded as Black, Asian, and other (mostly Mexican-Americans or Puerto Ricans) for minority students. It was concluded that: broad aptitude measures of the quantitative and verbal parts of the MCAT had greater predictive power for minority students than for majority students; measures of general aptitude were better predictors than measures of past achievement for minority students; the selectivity of the undergraduate college had a statistically significant positive effect on majority students' performance; the effects of medical school differences in relation to compensatory education programs were weak; and, for majority and minority medical students with equivalent premedical school characteristics, the majority students could be expected to score higher than the minority students on the NBME in two out of three cases. (Implications of this study were discussed). (MH)