The present study assessed the effects of neuroleptic medication on tests sensitive to frontal and non-frontal lobe function in schizophrenic patients. A test-retest design before and after initiation of neuroleptic treatment was used. The performance of schizophrenics was compared with that of matched normal controls. Schizophrenics performed more poorly than controls on most tests at both first and second testing. Patients' performance improved significantly between the test and the retest on the digit symbol subtest of the WAIS-R and on the Stroop 'color naming' subtest. Similarly, performance on the verbal fluency test and on the Rey complex figure recall tended to be better at the retest, although not significantly. The deficit on the Wisconsin Card Sorting Test (WCST) remained stable over time in patients. The result suggest that neuroleptics give no negative effects on cognitive functioning in schizophrenics.