Sudden death in athletes occurs because of the existence of hidden cardiovascular disorders which, during effort, may jeopardize the electrical stability of the heart, triggering ventricular tachycardia and/or fibrillation. Apart from rare conditions of ion channel diseases in the setting of a structurally normal heart, in which the disorder may be easily diagnosed on basal or stress test ECG, cardiac abnormalities at risk of causing sudden death may affect the aorta (Marfan syndrome), the coronary arteries (congenital coronary artery anomalies, premature coronary atherosclerosis), the myocardium (hypertrophic and arrhythmogenic cardiomyopathy), the valves (bicuspid aortic valve, mitral valve prolapse) and the conduction system (pre-excitation syndromes). These structural heart disorders may be detected by ECG and/or echo. The employment of these tools at pre-participation screening can help to identify concealed anomalies, which may play a major role in early diagnosis, risk stratification, and prevention of sudden death.