Although numerous studies have confirmed the presence of larger cerebral ventricles in schizophrenia, the locus of tissue loss remains elusive. By analyzing magnetic resonance scans with computerized image analysis, the authors determined gray and white matter volumes in the temporal lobes and prefrontal regions of 17 patients with schizophrenia and 17 age- and sex-matched normal subjects. The volume of temporal lobe gray matter was 20% smaller in the patients than in the control subjects. The lateral ventricular volume was 67% larger in the patients and, when normalized for brain size, correlated inversely with the volume of temporal lobe gray matter.