Thirty top level athletes, 30 athletic students and 30 sedentary controls underwent electrocardiographic and echocardiographic investigation. Resting ECG in athletes showed increased indices of hypertrophy compared to controls. The echocardiographic examination demonstrated an increase in left ventricular mass (LVM) of 47% in top athletes and 23% in athletic students compared to controls. The relationship between wall thickness and diameter was similar in all groups, as were parameters of systolic and diastolic left ventricular function at rest. There was no correlation between LVM assessed by echocardiography and ventricular ectopic activity assessed by Holter monitoring in this normotensive population. Highly significant correlations between ECG and echocardiographic parameters of hypertrophy were demonstrated.