Thirty-nine patients with schizophrenia, diagnosed according to DSM-III-R, who were under 15 years of age, were studied in two groups; 16 subjects with obsessive-compulsive symptoms during the prodromal phase, and 23 with no obsessive-compulsive disorders. The group with obsessive-compulsive symptoms during the prodromal phase was characterized by a higher ratio of males, higher incidences of perinatal and brain computed tomography (CT) abnormalities, fewer hereditary factors, longer duration of the prodromal phase, and a higher incidence of insidious onset and negative symptoms compared with the group without such prodromal symptoms. Schizophrenic patients with obsessive-compulsive symptoms during the prodromal phase were clinically distinct from those without, which suggests the possibility of subtype categorization.