Five patients (pts) with life-threatening ventricular tachyarrhythmias (idiopathic VF; 2 pts, Torsade de pointest; 1 pt, VT/VF after valve replacement; 2 pts) underwent surgical treatment of the automatic implantable cardioverter defibrillator (AICD). Implantation of an AICD was indicated for patients who survived circulatory arrest due to documented VT and/or VF. The patient should be medically refractory or medical treatment precluded by hemodynamic instability; other surgical treatment should not be possible. We selected myocardial electrode for sensing and small and large patch electrodes for defibrillating. VF/VT was induced 1 to 6 times for the measurement of defibrillation threshold (DFT). In all of our pts, the AICD appropriately discharged at postoperative EPS. In three of pts, the AICD discharged within the postoperative hospital phase, in two because of sinus tachycardia during treadmill test and restored sinus rhythm after non-sustained VT. As for complications, in one pt. with severe LV dysfunction, incessant form of VT/VF occurred after DFT testing and LV assist circulation and IABP were needed. In two pts, inappropriate discharge and in two, pericarditis were recognized postoperatively. It was considered that this system was effective for the treatment of life-threatening ventricular tachyarrhythmias but strict indication was necessary because of unsolved problems.