We report a case of sudden death due to cardiac conduction system injury from a blunt chest impact. A 20 year old male, kicked in the precordial region, lost consciousness, and was confirmed dead on arrival at a hospital emergency care unit. According to his friends, they played a golf competition accompanied with a physical punishment. The victim, losing the game, allowed the winner to give him several kicks in the chest. Although well prepared against each kick, he fell down instantaneously after the final impact, and death was confirmed at a hospital. There was no apparent sign of injury on the body surface. At autopsy, there was no evident subcutaneous or intramuscular hemorrhages, rib or sternum fracture. Subendocardial hemorrhage in the region of the atrioventricular node and a contusion extending from the posterior wall of the left ventricle to the upper ventricular septum were observed. Histological examination revealed injury of atrioventricular node and His' bundle. Although the cardiac injury including contusion of the myocardium itself was not so extensive, it was considered that arrhythmia was induced by the cardiac conduction system failure, which was considered to be the cause of death.