Aortic valve insufficiency with ventricular septal defect is usually treated by plication of the commissures. However, long-term deterioration is common. We propose a new technique that corrects the aortic annulus dilatation and the leaflet prolapse and reinforces the sinus of Valsalva. Two groups were compared: group I (29 patients) had plication of the prolapsed leaflet(s) and folding of the free edge; group II (26 patients) had triangular resection of the prolapse cusp, annuloplasty, and reinforcement of the aortic wall. The two groups were similar with regarding to preoperative clinical data. There was no perioperative mortality. Primary failure (aortic valve replacement) occurred in 8 patients in group I (28%) and in 2 patients in group II (8%). The rate of secondary failure was 31% in group I and 4% in group II. The actuarial rate of freedom from reoperation at 5 years is 55% in group I and 88% in group II (p less than 0.05). The late mortality was 6.5% in group I and 10.9% in group II (no difference). We conclude that aortic valve insufficiency with ventricular septal defect is a malformation of the aortic leaflets, the annulus, and the sinus of Valsalva, and that the proposed technique offers a better result than the usual methods in terms of residual aortic valve insufficiency.