Sudden cardiac death in the athlete is uncommon but extremely visible. In athletes under age 30, genetic heart disease, including hypertrophic cardiomyopathy, arrhythmogenic right ventricular cardiomyopathy, and ion channel disorders account for the majority of the deaths. Commotio cordis, involving blunt trauma to the chest leading to ventricular fibrillation, is also a leading cause of sudden cardiac death in young athletes. As the athlete ages, coronary atherosclerosis contributes to an increasing incidence of sudden death during sporting activities. For athletes with aborted sudden death or arrhythmia-related syncope, an implantable cardioverter defibrillator is generally indicated, and they should be restricted from most competitive sports. Participation in competitive athletics for athletes with heart disease should generally follow the recently published 36th Bethesda Conference Eligibility Recommendations for Competitive Athletes with Cardiovascular Abnormalities.