Between october, 1982 and december, 1986, 17 patients were implanted with an automatic defibrillator. The thoracic route was used in 6 patients with installation of an epicardial patch and an endocavitary electrode. The subcostal route was used in the remaining 11 patients, with 2 epicardial patches. The device, badly tolerated by 2 of the first 6 patients, created no problem in the 11 patients of the second group. One patient died of pulmonary embolism on the 6th post-operative day. At follow-up, there was no inappropriate triggering of the AID-B: 8 patients had neither arrhythmia nor shock, and 8 received from 2 to 55 shocks with documented arrhythmia. Two patients died suddenly: one after end of life of the device, the other after 3 years, while the device was still working. The implantable defibrillator technique has improved and local complications are now seldom observed. The device is reliable and constitutes an effective weapon against sudden death caused by ventricular arrhythmia.