Many different variables have been used in an attempt to predict performance in medical school, residency, and practice. The extensive literature on this subject has been reviewed and evaluated. Admission to medical school should not be based solely on grade point average and Medical College Admission Test scores because these offer no measure of extremely important noncognitive attributes. Although performance in the preclinical years is predicted by the grade point average and Medical College Admission Test scores, no such correlation exists for achievements in the clinical years, for postgraduate training, or as physicians. Thus, even though underrepresented minority applicants to medical school tend to have lower grade point averages and Medical College Admission Test scores than majority applicants, ultimate success in postgraduate training and as practicing physicians is equivalent to that attained by majority students.