Isolated ventricular septal defect (VSD) is a well know congenital heart anomaly. If discovered in infancy or early childhood surgical intervention can be of necessity depending on the size of the defect, to assure a healthy adulthood. The long-term results of surgical closure of VSD in childhood are good and after surgery the children are considered as equally healthy and physically fit as their peers. However, there is inconsistency in data regarding follow-up on this group of patients, in relation to exercise capacity as a measure of the cardiopulmonary function. To further approach this matter the post-operative cardiac factors of these patients have to be investigated.