Successful percutaneous transluminal angioplasty (PTA) of an internal mammary artery graft was performed in a 40 year old male patient who had recurrent angina soon after bypass surgery. Coronary angiography showed total occlusion of proximal portion of the left anterior descending artery and normal right coronary artery. Angiography of the left internal mammary artery graft revealed a tight stenosis (90% diameter narrowing) in the mammary artery at its insection into the left anterior descending artery.Angiography after the angioplasty demonstrated a widely patent graft (residual stenosis 10%) and translesional pressure gradient was 10 mmHg.