Anomalous origin of one pulmonary artery from the ascending aorta (AOPA) is a rare and potentially deadly anomaly. Little research, aside from case reports on APOA, has been published, especially for patients with late referrals. This study was a retrospective review of 57 patients with AOPA who underwent reimplantation of the pulmonary artery (PA) from 2009 to 2019. Two different reimplantation methods were used to correct the anomaly, including direct anastomosis in 36 patients and angioplasty with autologous tissue in 21 patients. The median age at repair was 2.8 months (range, 8 days to 3.6 years). In-hospital death occurred in 2 patients (3.5%). Five patients (9.1%) with a median age of 9.3 months (range, 5.2 months to 3.6 years) experienced a pulmonary hypertensive crisis. Patients older than 4.9 months were more likely to have a pulmonary hypertensive crisis (P= .001). The 2-year freedom from postoperative PA stenosis rate was 75.3% in patients who underwent direct anastomosis and 46.8% in patients who underwent autologous tissue angioplasty (χ2= 4.878; P= .027). Angioplasty with autologous tissue (hazard ratio, 5.03; 95% confidence interval, 1.61 to 15.71; P= .005) and an innately smaller diameter of the aberrant PA (hazard ratio, 0.65; 95% confidence interval, 0.45 to 0.92; P= .015) were 2 independent risk factors for postoperative PA stenosis. Surgical reimplantation of the PA in patients with AOPA has resulted in favorable early and midterm outcomes. Pulmonary hypertensive crisis occurs more commonly in patients who receive a diagnosis after the age of 4.9 months. Reimplantation with autologous tissue augmentation and an intrinsically smaller diameter in affected PAs are 2 independent risk factors for postoperative PA stenosis.