Background: Left ventricular outflow tract obstruction(LVOTO) in the management of transposition of the great arteries(TGA) with ventricular septal defect(VSD) is still major concern. The arterial switch operation(ASO) can be one of the surgical options in these patients, but there are no clear indices. Here we report our experience on ASO for patients with TGA with LVOTO and VSD. Materials and Methods: Among 227patients who underwent an ASO for TGA between October 1989 and January 2007, fifteen(6.6%) had VSD and LVOTO. Age and weight at operation ranged from 20days to 3777 days (median : 234days) and 2.2kg to 33kg (median : 9.4kg), respectively. Median follow-up duration was 49.0 months(15 ~ 206months), and in all patients, echocardiographic evaluation was performed pre- and postoperatively. Results: There were two early deaths(13.3%) and no late death. Mean postoperative LVOT systolic pressure gradients at discharge and follow-up decreased significantly compared with preoperative one (48.8 짹 28.6mmHg  22.5 짹 18.2 mmHg and 24.4 짹 28.4mmHg, p<0.01 and p=0.028). Mean postoperative aortic z-value of neoaortic annulus showed a tendency to increase compared with preoperative aortic z-value of pulmonary annulus (1.56 짹 1.96  4.24 짹 2.37, p=0.051). 3 patients underwent 4 reoperations for recurrent LVOTO. 5-year reoperation free survival rate was 82.5%. Neoaortic insufficiency was observed in three patients, and all were grade 1. All patients were in NYHA functional class 1 at last follow-up, and all but one patient, who need anticoagulation for mechanical prosthesis, do not need any medication. Conclusions: In the management of TGA with VSD and LVOTO, the anatomic features of LVOTO and aortic z-value of pulmonary annulus must be addressed to determine the application of an ASO. In selected cases, as was shown in our study, ASO can be a good surgical option even without LVOTO relieving procedures.