Interrupted aortic arch is a poor prognosis cardiac anomaly with nearly 100 percent mortality if not recognized and treated early. The associated intracardiac lesions often lead to death if only the arch defect is repaired. Several recent reports have described patients with interrupted aortic arch who were treated as infants by primary repair of the arch defect with simultaneous repair of the intracardiac lesions. The improved survival data from these series have been attributed to the simultaneous repair of both lesions. We report herein on nine patients with both interrupted aortic arch and ventricular septal defect seen at Children's Hospital and Medical Center in Seattle from 1979 to 1987. Three patients had partial expression of DiGeorge's syndrome. All patients underwent primary repair of the interrupted aortic arch with concomitant pulmonary artery banding during infancy (mean age 18 days, range 2 days to 4 months). Operative mortality was 11 percent (1 of 9 patients). Eight patients had eventual repair of the ventricular septal defect (mean age 18 months, range 6 to 29 months) with one death occurring at 5 months postoperatively (12 percent mortality). The overall mortality of these nine patients was 22 percent. Staged repair of interrupted aortic arch with associated ventricular septal defect can be performed with results comparable to simultaneous primary repair in infancy. The improved survival from either approach is more likely to be attributable to improved perioperative stabilization, particularly the use of prostaglandin E.