Regular participation in intensive physical exercise is associated with electro-morphological changes in the heart. This benign process is called athlete's heart. Athlete's heart resembles few pathologic conditions in some aspects. So differentiation of these conditions is very important which otherwise may lead to a catastrophic event such as sudden death. The most common causes of sudden death in young athletes are cardiomyopathies, congenital coronary anomalies, and ion channelopathies. The appropriate screening strategy to prevent sudden cardiac death in athletes remains a challenging issue. The purpose of this review is to describe the characteristics of athlete's heart and demonstrate how to differentiate it from pathologic conditions that can cause sudden death.