We present a case of percutaneous coronary intervention in a 4-month-old infant with both severe coronary stenosis and acute heart failure after arterial switch operation for transposition of the great arteries. Under extracorporeal membrane oxygenation, balloon angioplasty of the left coronary artery with a 2.0 × 15-mm balloon and stent implantation on the right coronary artery with a 2.25 × 26-mm stent were performed successfully. Echocardiography after the intervention showed recovered cardiac function and no complications.