Pimozide and haloperidol are typical antipsychotics. They share a similarity in pharmacotherapeutic and adverse effect profiles. Cardiovascular effects may be seen as alterations in heart rate, blood pressure, and cardiac conduction. Conduction disturbances may occur ranging from asymptomatic prolongation of the QT interval to fatal ventricular arrhythmia. So in the case of anti psychotics overdose, the patient must be carefully monitored by continuous electrocardiography (ECG). We experienced a 34-year-old woman of schizophrenia with recurrent ventricular tachycardia after pimozide and haloperidol overdose. Initially she was slightly drowsy, however her ECG showed normal sinus rhythm. After 6 hours on emergency department entrance, her ECG monitoring showed ventricular tachycardia and we successfully defibrillated. There were five times events of ventricular arrhythmia during the in-hospital stay. She was discharged 5 days later without any other complications.