Objectives: The transannular patch used to relieve right ventricular outflow tract obstruction in children with tetralogy of Fallot may result in pulmonary insufficiency. We hypothesized that pulmonary valve cusp augmentation with pericardium would decrease pulmonary insufficiency and improve the early outcome for transatrial-transpulmonary tetralogy of Fallot repair requiring transannular patch. Methods: Since November 2001, 41 patients with tetralogy of Fallot and 2 patients with isolated pulmonary valve stenosis had relief of right ventricular outflow tract obstruction with either a transannular patch plus pulmonary valve cusp augmentation (n = 18) or a transannular patch alone (n = 25). Data were retrospectively collected. Results: The median age (5.3 vs 3.2 months; P = .09) and weight (6.4 vs 5.2 kg; P = .3) were similar for the cusp augmentation and transannular patch groups, respectively. The diameter of the pulmonary valve annulus (6.4 vs 6.0 mm; P = .57) and the McGoon index (1.47 vs 1.69, P = .75) were also similar. The mean aortic clamp time (48 ± 18 minutes vs 52 ± 19 minutes; P = .46) and median cardiopulmonary bypass time (89 vs 91 minutes; P = .9) did not differ. One patient with a transannular patch died of multiorgan system failure. Patients with a pulmonary valve cusp augmentation had a shorter duration of intubation (1 vs 3 days; P < .001) and intensive care unit stay (2 vs 8 days; P < .001). Thirteen patients with a transannular patch and 1 patient with a pulmonary valve cusp augmentation required inotropic support for more than 72 hours (P = .001). Discharge echocardiograms demonstrated moderate or severe pulmonary insufficiency in 5 patients with a pulmonary valve cusp augmentation and in 21 patients with a transannular patch (P < .001). At 7.5 months, 3 patients (17%) with a pulmonary valve cusp augmentation had progression of pulmonary insufficiency. Conclusions: Augmentation of a pulmonary valve cusp reduces the incidence of clinically significant postoperative pulmonary insufficiency. This technique may improve the early outcome for children with tetralogy of Fallot requiring a transannular patch.