Implantable cardioverter-defibrillators (ICD) in adults have shown to be safe and effective for both primary and secondary prevention of sudden cardiac death (SCD). In children and patients with congenital heart disease prospective trials to evaluate the safety and efficacy of these devices are still lacking. This review will discuss the different aspects of ICD therapy in children with regard to current indications, effectiveness, problems related to size and growth, inappropriate shock therapy, and quality of life.