There are risks associated with any surgery, and surgical treatment of tetralogy of Fallot carries the same risks of anaesthesia, extracorporeal circulation and complications associated with surgery as any other procedure. However, the surgical technique is now well established and the mortality rate for children with pure tetralogy of Fallot is around 2% to 3%. Children younger than 3 months or older than 4 years and children with pulmonary artery hypoplasia are at high risk of surgery. Overall, however, surgery is the most important treatment for tetralogy of Fallot, and the benefits far outweigh the risks if the child is eligible for surgery.