Some level of frontal and callosal dysfunction has been reported in patients with schizophrenia. In the present study 68 normal controls and 117 schizophrenic patients were administered the Wisconsin Card Sorting Test (WCST), which involves the function of the frontal areas, and the Auditory Comprehension Test (ACT) which involves the corpus callosum and to a lesser degree attention and mnesic mechanisms. WCST correctly discriminated 69.8% of schizophrenics and 74.2% of controls, ACT 86.7% of schizophrenics and 90.2% of controls. Moreover, schizophrenics correctly classified by the WCST performed more poorly than schizophrenics incorrectly classified by the WCST on the related ACT indices for the attention and mnesic mechanisms. There were no differences in present age, age at onset, duration of the illness, diagnostic subtype and course of the disease between correctly and incorrectly classified schizophrenics by the WCST and the ACT. These data indicate a prevalent malfunctioning of attention and mnesic mechanisms in schizophrenia. Finally there seems to be no relationship between these neurofunctional abnormalities and demographic and clinical characteristics of the disease.