The Fontan procedure has afforded improved surgical repair for several complex congenital cardiac defects, including tricuspid atresia and single ventricle. Through surgical creation of a connection between the RA and the RV or PA, adequate pulmonary perfusion can be achieved without an RV. Although it is not an anatomic connection, the Fontan procedure is a more physiologic approach than the previously used shunt procedures. Systemic venous return and PVR are effectively separated within the heart, pulmonary blood flow is assured through an RA-to-PA connection, and ventricular volume overload is avoided. The procedure has been effective in relieving cyanosis and has resulted in improved levels of exercise tolerance after surgery.