Objective To investigate clinical outcomes of one-stage repair for patients with persistent truncus arter-iosus who missed optimal timing of surgery. Methods We retrospectively analyzed clinical data of 12 patients with persistent truncus arteriosus who had missed optimal timing of surgery and were admitted to Wuhan Asia Heart Hospital between June 2003 and August 2011. There were 7 male patients and 5 female patients with their median age of 4.5 （0.6-14.0）years and median body weight of 23 （6-36）kg. All the patients underwent one-stage surgical repair. There were 9 patients with Van Praagh type A1，2 patients with type A2，and 1 patient with type A4 persistent truncus arteriosus. There were 2 patients with anomalous origin of coronary artery，2 patients with moderate truncal valve insufficiency，and 3 patients with moderate tricuspid valve insufficiency which required concomitant surgical repair. All the patients received preoperative right heart catheterization which showed severe pulmonary hypertension. The median pulmonary-systemic blood flow ratio （Qp/Qs ratio） was 2.42 （1.50-5.26），and median pulmonary vascular resistance was 8.1 （4-12） Wood units. All the patients showed a positive pulmonary vasodilator response to oxygen. Right ventricular outflow tract （RVOT） reconstruction was achieved using a valved conduit in 7 patients and a valved patch in 5 patients. Results There was no in-hospital death in this group. Three patients had transient pulmonary hypertensive crisis during postoperative intensive care and were healed after proper treatment. Early postoperative pulmonary artery pressure monitoring in all the patients showed that main pulm-onary artery systolic pressure/radial artery systolic pressure was 0.48±0.12. All the 12 patients were followed up for 48（12-91）months. There were 10 patients with New York Heart Association （NYHA） classⅠand 2 patients with NYHA classⅡ during follow-up. One patient received reoperation for residual ventricular septal defect and right ventricular failure.Two patients required long-term medication treatment for high pulmonary vascular resistance and right ventricular failure. The latest echocardiography during follow-up showed that average pressure gradient across RVOT was 21 （16-42） mm Hg in patients with valved conduit for RVOT reconstruction and 18 （10-28） mm Hg in patients with valved patch for RVOT reconstruction. None of the patients required reoperation for RVOT obstruction. Pulmonary regurgitation was less than moderate degree in all the patients. Two patients with anomalous origin of coronary artery didn’t have symptoms or electrocardiogram changes of myocardial ischemia during follow-up. Conclusion For patients with persistent truncus arteriosus who missed optimal timing of surgery， one-stage repair can achieve good early and intermediate clinical outcomes，but long-term follow-up is needed to observe truncal valve regurgitation and right ventricular function.