A 49-year-old man was referred for further treatment of sustained monomorphic ventricular tachycardia (VT) associated with cardiac sarcoidosis. During an electrophysiologic study (EP), dl-sotalol suppressed the spontaneous VT and prevented induction of VT. However, when predonisolone treatment was started, monomorphic VT recurred frequently. To terminate the VT, a temporal pacing lead was placed at the apex of the right ventricle, and programmed electrical stimulation was attempted from the lead. During the EP study, 2 different monomorphic VTs were repetitively induced and both types were able to be terminated by rapid ventricular pacing; in one of the VT morphologies, constant and progressive fusion was obvious during the ventricular pacing. Some monomorphic VTs associated with cardiac sarcoidosis are due to reentry with an excitable gap, but the clinical efficacy of EP-guided antiarrhythmic drug treatment seems to be less certain during steroid therapy. In the present case, a defibrillator device was implanted to prevent a possible arrhythmic event.