Sudden cardiac arrest/death in pediatric patients is a rare but potentially preventable event. Cardiomyopathies and channelopathies are the most common causes which are detectable with ECG and transthoracic echocardiography in asymptomatic subjects. Coronary artery anomalies are a rare cause of sudden cardiac arrest/death, but these events suggest that ECG and echocardiography, focused on the site of origin of the coronary arteries, should be both part of the screening tool of young athletes. Finally, the rare cardiac arrest events in young patients with ventricular preexcitation without prior symptoms or markers of high risk suggest that transcatheter ablation should be considered in all pediatric patients with ventricular preexcitation because it can eliminate the small long-term risk of sudden cardiac arrest/death, but a careful consideration of the most appropriate timing is mandatory.