Moldin et al. (1) have identified a cluster of Minnesota Multiphasic Personality Inventory (MMPI) scales that discriminate adolescents at risk for schizophrenia from those not at risk. The present study examines how well Moldin's scales predict schizophrenic decompensation in a sample of 207 Danish adolescents at high genetic risk for schizophrenia. Subjects were assessed using a modified, 304-item MMPI in 1962 (mean age=15.1 years) and diagnosed in 10-year and 25-year follow-ups. Premorbidly. schizophrenic subjects (n = 31) scorcd higher than subjects with no mental illness on the frequency (F) and psychoticism (PSY) scales. When paranoid and non-paranoid preschizophrenics were separated, three scales (F, Pz (paranoid schizophrenia) and PSY) significantly discriminated paranoid preschizophrenics. Discriminant function analyses confirmed these results. It is concluded that the MMPI may be useful for identifying schizophrenia premorbidly.