The implantable cardioverter defibrillator (ICD) has proved to be effective in patients at risk of sudden cardiac death (SCD). Because of the development of more effective lead- and defibrillator systems the surgical implantation modes have changed from extensive operative interventions (sternotomy, lateral thoracotomy) to less traumatical (subxiphoidal/subcostal approach) and less invasive (transvenous) techniques. Procedures with less operative damage may be offered to patients with reduced cardiac function. However, the kind of operative procedure to be performed must be decided individually. The different system configurations, their advantages and disadvantages as well as their complications are surveyed and discussed in the light of our patient population, 102 cases between 1984 and 1991, and the literature. Even when the "non thoracotomy" implantations will become the favoured method, the standard incisions by thoracotomy will still be of importance. Considering that major complications occur also in transvenous implant procedures and that cardiac operations have to be performed in 20-30% of the patients simultaneously, we suggest--following the recommendations of the North American Society of Pacing and Electrophysiology (NASPE)--that the devices be implanted exclusively in units for cardiac surgery in cooperation with rhythmologically well-trained cardiologists.