Recent studies suggest that both executive dysfunction and personality traits combine with symptoms to affect the social outcome of persons with schizophrenia. This study was designed to investigate how personality traits influence executive function in schizophrenia. Forty-four patients with schizophrenia and twenty-two healthy subjects were assessed for personality using the temperament and character inventory. Different aspects of executive function were assessed using the Auditory Digit Span (forward and backward) and the Wickens' test for proactive interference and release. The results showed that the influences of the various temperament dimensions on specific aspects of executive functions differ between patients and healthy subjects. On some dimensions, schizophrenia appears to reduce the cognitive differences related to temperament. On other dimensions, schizophrenia tends to reverse the cognitive differences related to temperament observed in healthy people. These results suggest that the temperamental profile of schizophrenia patients may well be of important prognostic value in the planning of cognitive enhancement therapy.