Numerous studies have shown evidence of cerebral ventricular enlargement in schizophrenia and its relationship to severity of clinical symptoms and psychosocial dysfunction. In this large prospective study, 88 noninstitutionalized DSM-III-R schizophrenic patients were administered a CT scan and rated for positive and negative symptomatology and premorbid adjustment. The CT scans from 14 healthy controls were used for comparison of cerebral ventricular measures. Patients had an enlarged ventricle to brain ratio of the anterior portion of the lateral ventricles, the frontal horns, compared with controls. Patients with larger frontal horns had more severe negative symptoms and poorer premorbid childhood adjustment. The area of the main body of the cerebral lateral ventricles, though not elevated in patients, was correlated with the total number of prior hospitalizations. These results support the hypothesis of a structural and functional “frontal” deficit in schizophrenia.