Follow-up cardiac catheterization and angiography was performed in 23 patients after complete, staged repair of pulmonary atresia with ventricular septal defect and multiple systemic-to-pulmonary collateral arteries. Time interval from repair varied from 0.2 to 89 months (mean 26 months). Major residual anomalies of arborization of the pulmonary arteries, with or without pulmonary vascular disease, were present in six patients, two of whom had die patch on the ventricular septal defect perforated because of systemic or suprasystemic right ventricular pressure in the early postoperative period after repair. Both of these children later died, while the other four patients were found to have moderately to severely elevated ventricular pressure ratios and pulmonary arterial pressure measurements, though they are all alive at follow-up intervals from 20 months to 6.8 years. The remaining 17 patients all had hemodynamically satisfactory or good results, with pulmonary arterial mean pressures ranging from 8 to 30 mm Hg (mean 22 mm Hg) and pressure ratios between the ventricles from 0.24 to 0.75 (mean 0.43)—the higher ratios generally reflecting gradients across the conduit valve. Angiography demonstrated that the hypoplastic pulmonary arteries increased in size to normal dimensions, during staging, in most patients, though abnormalities of arborization persisted in several. Analysis of the data from the entire cohort of 58 patients, who were accepted for staging towards repair, showed a significant association between early age at entry to the program and likelihood of complete repair being achievable.