Tardive dyskinesia (TD) is a neurological movement disorder. It is induced by neuroleptic drugs but at least some of these movement are due to dysfunction of frontal lobe in Schizophrenic patients. In this research, we assessed the function of prefrontal area in Schizophrenic patients with and without TD to answer the following questions: Is there any relationship between TD and dysfunction of frontal lobe? Is there any way to recognize patients that are vulnerable to TD and to prevent it> In this research 100 Schizophrenic in-patients were chosen (50 with TD and 50 without it). They were assessed with WCST that is a standard neuropsychologic test for assessment of prefrontal function. Results were statistically analyzed with T-test and Chi-square, SPSS. Patients with TD compared to patients without TD had significantly (P~0) increased errors in WCST that showed dysfunction of frontal lobe in patients with TD. It appears with WCST in early stages of Schizophrenia we can recognize patients with dysfunction of frontal lobe and vulnerable to TD and prevent development and progression of TD with atypical antipsychotics and regular monitoring of abnormal movements in these patients.