Objective To investigate the risk factors of neoaortic regurgitation (NAR) after the arterial switch operation (ASO) for transposition of the great arteries (TGA). Methods This retrospective study enrolled 229 patients with TGA who underwent ASO from January 2008-2013 in Fu Wai Hospital, including 173 males and 56 females with an average age of 7.8±15.9 months (range, 3 days to 93.9 months; median, 47 days) and an average weight of 6.3±4.2 kg (range, 4 to18 kg; median, 2.4 kg). Results The mean follow-up was 62.5±31.1 months and the shortest was 36 months. Twenty eight patients (12.2%) suffered at least moderate NAR. In Kaplan-Meier survival analysis, probability of freedom from at least moderate NAR was 100.0%, 100.0%, 99.6%, 95.3% at year 1, 2, 3 and 5, respectively. Univariate analysis revealed that weight and frequency of preoperative pulmonary arterial hypertension and previous pulmonary artery banding in patients with at least moderate NAR before ASO were more than those of other patients (8.3±5.6 kgvs. 5.8±4.3 kg,P=0.006; 50.0%vs. 20.4%,P=0.001; 28.6%vs. 10.4%,P=0.013). Multivariate analysis showed that previous pulmonary artery banding (HR=3.8,P=0.005) and preoperative pulmonary arterial hypertension (HR=16.5,P<0.001) were risk factors of NAR. Conclusion The incidence of at least moderate NAR after ASO is favorable. At least moderate NAR is associated with preoperative pulmonary arterial hypertension and previous pulmonary artery banding.