Surgical repair of type B interruption of the aortic arch and ventricular septal defects (VSD) in the newborn period is difficult and the optimal approach is controversial. We report here our early and late results using a two-staged approach in the repair of these lesions in seven consecutive neonates whose weights ranged from 2.9 to 3.8 kg and who were all less than 21 days of age. Each underwent aortic arch reconstruction or cardiopulmonary bypass with placement of a large (6 to 10 mm) polytetrafluoroethylene (PTFE) graft and pulmonary artery bleeding for interruption of the aortic arch (six) or extreme hypoplasia (one) of the arch. All seven (100%) survived the first-stage operation. No significant (> 10 mm Hg) conduit gradient was found in the seven patients studied 3 to 18 months postoperatively. One death occurred in a patient at 1 year of age with severe subaortic stenosis. Six patients subsequently underwent closure of VSD and removal of pulmonary artery band, with five survivors (83%). The operative death occurred in an infant in whom pulmonary hypertension developed from an inadequate pulmonary artery band. One late death occurred at home when a tracheostomy tube, required because of severe tracheomalacia, became plugged. The long-term survival rate for completion of both stages is 57%. We conclude: (a) Aortic arch reconstruction and pulmonary artery banding can be reliably performed even in criticaly ill infants, and the 8 or 10 mm grafts be adequate for several years. (2) Significant subaortic stenosis occurred in only one patient. (3) Pulmonary artery banding was the greatest source of difficulty, and distortion of the pulmonary arteries, inadequate banding, and compression of the trachea were all seen. Therefore, the staged repair will provide good results with this complex anomaly, and most of the problems associated with this approach may be eliminated by early second-stage repair.