The 12-lead electrocardiogram of a 17-year-old African professional soccer player had signs of left ventricular (LV) hypertrophy and deeply inverted T waves in the inferior and precordial leads. Two-dimensional echocardiography showed mild LV hypertrophy with normal cavity size consistent with nonobstructive hypertrophic cardiomyopathy. After 5 months of complete discontinuation of training, the electrocardiogram normalized; however, the echocardiogram was unchanged. Subsequently, and contrary to our advice, the athlete resumed training and professional soccer. One year later the electrocardiogram again showed a similar and markedly abnormal pattern without cardiac dimensional changes.