The case of a young adolescent who suffered a sudden death while playing soccer is described. At necropsy a long intramyocardial segment of the obtuse marginal branch of the left coronary artery was found, with fresh ischemic damage in the surrounding myocardium. We comment about negativity of the tests the boy had undertaken because of a single syncopal episode he suffered in similar circumstances. Those tests included two 24-hour Holter monitorings, a maximal electrocardiographic stress-test and an electrophysiologic study. In no occasion did he complain of angina pectoris.