In order to test the hypothesis that a poor performance in the Wisconsin test (WCST) may be an indicator of liability to schizophrenia, we compared the WCST performances of patients with DSM III-R schizophrenia, normal controls, and patients with schizotypal personality disorder (SZT PD). While schizophrenic patients performed significantly worse than subjects in the other two groups, schizotypal and normal subjects showed no significant differences in the WCST execution. Moreover, patients with SZT PD with or without positive family history for the schizophrenic spectrum had similar WCST performances. Our observations are in keeping with other studies employing the WCST in paradigms of heightened liability to schizophrenia, and suggest that a poor performance in the test is more probably a feature of the disease process, than a trait marker of vulnerability to the illness demonstrable in high-risk subjects.