The anterior horn and lateral ventricular sizes of the brain CT were selected for measurement and comparison between 47 schizophrenic patients and 48 neurotic cases, which constituted the control subjects. The ventricular brain ratio (VBR) and the linear ratio (LR 1-6) in multiple age groups were calculated, analyzed and compared using the Student's t test, the two-way ANOVA and Bonferroni's methods. It was found that the VBR of the anterior horn and modified bicaudate cerebroventricular index of the teenage schizophrenics were significantly greater than those of the teenage controls (p less than 0.01) and the ventricular sizes were not associated with the different stages of age except for the cases of the teenage group. These results support the hypothesis of previous investigators that the ventricular enlargement is present early in the course of schizophrenia and provide additional evidence that in teenage schizophrenic patients there is a tendency of the enlargement of the anterior horn of the lateral ventricle which may be related with a morphological vulnerability in the prefrontal cortex.