Results of banding of the pulmonary artery have been reviewed in 87 patients who because of increased pulmonary blood flow manifested various signs of cardiac insufficiency or in whom we desired to avert the threat of increased pulmonary vascular resistance. In this group of infants and young children open cardiac correction of the underlying defect is associated with a high risk. Survival was better in infants older than 6 months of age. Simpler defects were not associated with a higher survival rate. Survival has improved considerably with greater experience. The most important factor in the increased survival has been selecting the degree of pulmonary artery constriction which is sufficient to give a sustained 15% to 25% rise in systemic systolic arterial pressure.