Surgical therapy for tetralogy of fallot is one of the success stories of the early era of cardiac surgery. Despite the many advances of the ensuing fifty years, such as new techniques for imaging, extension of surgical therapy to the neonatal period, and improved treatment in the intensive care unit, there has been an increasing recognition that the outcomes for many patients over the long term remain less than optimal. Mortality for surgical correction of tetralogy of Fallot, even in very small neonates, approaches zero at most institutions. Patients remain at risk, however, for right ventricular dysfunction, congestive heart failure, and an ongoing need for future therapeutic interventions, including cardiac catheterization and re-operation. Surgical reconstruction of the abnormal subpulmonary right ventricular outflow tract often results in pulmonary insufficiency and scarring, leading to ventricular volume overload and dysfunction. Postoperative right ventricular dysfunction may be associated with congestive heart failure, poor exercise tolerance, arrhythmias, and sudden death. The chapters which follow in this section of our supplement focus on the current state of knowledge concerning treatment and management of patients with pulmonary insufficiency following surgical repair of tetralogy of Fallot. There is considerable controversy concerning the clinical significance of pulmonary insufficiency; there is no standard technique for the assessment of right ventricular function; and there are considerable disagreements concerning the optimal timing of surgical re-intervention to replace the pulmonary valve. I believe that the reviews will help clarify these important issues.