A 1-yr-old girl underwent a living-related liver transplant, with reconstruction of hepatic artery of 2 mm in diameter under microscopy. She developed intestinal perforation requiring closure on day 4 post-transplant and suffered from hepatic artery stenosis (HAS) on post-transplant day 9. Conservative therapies, such as intravenous or transluminal administration of anti-coagulants, vasodilators or fluids, were unsuccessful and caused remarkable general edema and multiple arrhythmias as a result of increased preload. On day 15 post-transplant, because flow velocity was remarkably reduced (as shown by Doppler ultrasound) the patient underwent percutaneous transluminal angioplasty (PTA) using a kit for coronary angioplasty. The balloon catheter was inflated [first: 1.5 mm diameter, 4 atmospheric pressure (a.p.) for 30 seconds (s); second: 2.0 mm diameter, 4 a.p. for 30 s; third: 2.5 mm diameter, 10 a.p. for 30 s]. The stenosis was successfully dilated without any complication. The patient has been doing well with normal liver functions for 4 months after PTA. From this experience, PTA can be performed for HAS after liver transplantation, even in an infantile case, with a careful technique and a special device.