Abstract: Cognitive dysfunction has been recognized as an important clinical feature of schizophrenia. The possible pharmacological effect of neuroleptics on cognitive and psychomotor function including driving ability is crucial for rehabilitation of schizophrenic patients. Atypical neuroleptics such as risperidone have been shown to improve cognitive deficits in schizophrenics. We conducted a naturalistic nonrandomized clinical study to determine the effect of risperidone on psychomotor function compared to haloperidol in schizophrenic patients. In this study the psychomotor performance of 26 patients, who met the ICD-10 and DSM-IV criteria for schizophrenia, was assessed by means of ART-90, a computer-based Act & React Testsystem. 11 patients were on risperidone (mean dosage 4.0 mg) and 15 patients on haloperidol (mean dosage 10.5 mg). Patients were examined at discharge after psychopathological stabilization. In some relevant items the patients in the haloperidol group showed more impaired performance compared to the patients in the risperidone group. These preliminary data indicate a possible beneficial effect of risperidone compared to haloperidol on psychomotor performance and driving ability. Further randomized trials are necessary.