Background For children with congenital aortic stenosis (AS) who are selected for biventricular repair, valvuloplasty can be achieved by surgical aortic valvuloplasty (SAV) or by transcatheter balloon aortic dilation (BAD). A retrospective study was undertaken to compare the effectiveness of BAD versus SAV, evaluating the long-term survival, incidence of aortic valve restenosis or aortic insufficiency (AI) or both, and freedom from reoperation for repeated valve repair or replacement. Neonates less than 2 months of age were excluded from this comparison. Methods We reviewed the outcomes of children undergoing repair by SAV (n = 89) and BAD (n = 69) at our institution during a recent 20-year period. Clinical and echocardiographic follow-up were analyzed. The patient groups were compared with regard to the persistence or recurrence of postoperative aortic gradients and valve insufficiency and valve-related reintervention, including aortic valve replacement (AVR). Results There was no significant difference between the groups with respect to mean age, body surface area, valve anatomy, sex, and preoperative gradients. Our data demonstrate that gradient reduction, AI, and the need for reintervention were worse for BAD. Aortic gradients at last follow-up were similar in both cohorts, but return of a significant gradient occurred sooner for patients who had BAD. Aortic gradient at discharge was significantly better for the patients who underwent SAV. Kaplan-Meier analysis showed that at 10 years, comparison of SAV and BAD was as follows: freedom from reintervention, 72% versus 53% (p = 0.02) and freedom from AVR, 80% versus 75% (p = 0.32). Conclusions BAD yields less gradient reduction, more postprocedural AI, and a shorter interval between initial and subsequent reintervention than does SAV. Our results demonstrate that SAV is safe and effective and that residual gradients and degree of AI are low. After SAV, the need for AVR can usually be delayed until the child is significantly older. The long-term functional stability after SAV is excellent. BAD in comparison is associated with an increased frequency and severity of AI and the need for earlier reintervention and valve replacement. SAV should be offered to all patients beyond the newborn period because it gives superior and longer lasting palliation.