A comparison of schizophrenic, autistic, and conduct disordered children, ages 5.2 to 12.10 years, is presented. Diagnosis was made by the authors in all cases using DSM-III criteria. The children were compared on a variety of variables, including pre- and perinatal complications, intellectual functioning, and behavioral profile. Findings indicate that children under 12 years of age can be diagnosed as having schizophrenic disorder by DSM-III criteria. All schizophrenic children had a disorder of thinking and most had hallucinations (83.3%), while delusions were somewhat less frequent (54.2%). Schizophrenic children differ from autistic children on most variables, although there is some overlap.