SummaryObjectives: To assess the incidence and causes of ICD shocks in children and adolescents and their impact on quality of life (QoL).Methods: From March, 1997 to February, 2006 29 patients (15.7 ± 5.4 years of age) underwent ICD implantation. Resuscitated cardiac arrest (41.5%), sustained ventricular tachycardia (27.6%), and primary prophylaxis of sudden cardiac death (30.9%) were the indications for ICD implantation. The number of therapies was assessed by interview and using the ICD telemetry. The SF-36 questionnaire was used to assess QoL, which was compared to that of healthy individuals. The Kaplan-Meier method was used for the analysis of shock-free survival.Results: After 2.6 ± 1.8 years of follow-up, eight (27.6%) patients received 141 appropriate shocks due to polymorphic ventricular tachycardia (VT) (6) or ventricular fibrillation (VF) (2), and 11 (37.9%) received 152 inappropriate shocks due to supraventricular tachyarrhythmias (8) or oversensing (3). Appropriate shock-free survival expectancy was 74.2% ± 9.0 and 66.7% ± 10.7 after one and three years, respectively. Decreased QL was observed as regards physical functioning (61.7 ± 28.7), vitality (64.7±19.1), mental health (65.9±22.7) and emotional aspects (66.7±38.5). All patients reported fear and concern related to the ICD. Conclusion: Despite the great efficacy of this therapy, the high incidence of shocks interfered with QoL and adaptation to the device.