Exercise training and sports participation is an important part of the physical, psychological and metabolic growth of any child and adolescent, and this is also true for patients with congenital heart disease (CHD). As one can expect, exercise tolerance varies widely according to the CHD and to the treatment received, but the functional result achieved in the single patient is more important. Individual counselling is necessary and should be based on observations/results of thorough cardiovascular assessment. Exercise testing is the ideal tool to identify patients in whom exercise may induce arrhythmias or haemodynamic instability. In general, some degree of aerobic, isometric exercise training can be granted to most patients operated on for CHD. Serial evaluations may be required because of changing haemodynamic and functional status with time.