The aim of this study was to analyze the relation between the magnitude of training-induced left ventricular (LV) hypertrophy and the frequency and complexity of ventricular tachyarrhythmias in a large population of elite athletes without cardiovascular abnormalities. Ventricular tachyarrhythmias are a common finding in athletes, but it is unresolved as to whether the presence or magnitude of LV hypertrophy is a determinant of these arrhythmias in athletes without cardiovascular abnormalities. From 738 athletes examined at a national center for the evaluation of elite Italian athletes, 175 consecutive elite athletes with 24-hour ambulatory (Holter) electrocardiographic recordings (but without cardiovascular abnormalities and symptoms) were selected for the study group. Echocardiographic studies were performed during periods of peak training. Athletes were arbitrarily divided into 4 groups according to the frequency and complexity of ventricular arrhythmias during Holter electrocardiographic monitoring. No statistically significant relation was evident between LV mass (or mass index) and the grade or frequency of ventricular tachyarrhythmias. In addition, a trend was noted in those athletes with the most frequent and complex ventricular ectopy toward lower calculated LV mass. In conclusion, ventricular ectopy in elite athletes is not directly related to the magnitude of physiologic LV hypertrophy. These data offer a measure of clinical reassurance regarding the benign nature of ventricular tachyarrhythmias in elite athletes and the expression of athlete's heart.