The validity of predictors of academic performance in six postgraduate fields were compared. The fields included three liberal arts areas and three professional areas: arts and humanities, biological and physical science, social science, law, medicine, and business. The predictors included information about students' backgrounds, self-conceptions, values, nonacademic achievements, and curricular patterns as well as admissions test scores and grades. In most fields, grades were predicted by academic ability and by prior achievement, self-confidence, and previous accomplishment in the field. Background variables predicted grades only in law and arts and humanities. The predictive power of admissions tests varied from field to field.