Sudden death in athletes is a global problem. Although it is a relatively rare phenomenon (1/100,000 persons), when it does occur, it is often as an incomprehensible event. In fact, it strikes subjects who presumably should be much healthier than the general population. In the previous 20 years, many authors have studied this problem in an attempt to understand the causes and prevent these events, and it has been determined that, in the vast majority of cases, athletes who die suddenly have an underlying heart disease (arrhythmogenic cardiomyopathy, hypertrophic cardiomyopathy, coronary anomalies, channelopathies, etc.). In most cases these diseases do not produce major symptoms and do not preclude sports activity even at the highest levels, although they do increase the incidence of sudden death. How to discover these diseases in asymptomatic athletes is a hotly debated issue. In particular, there is controversy as to whether all athletes should undergo detailed medical screening, including electrocardiogram, or whether the costs of this screening are too high in relation to the event incidence. The purpose of this book is to accurately analyze the causes of sudden death in athletes and to provide cardiologists and sports physicians with useful tips on how to identify at-risk individuals.