A 67-year-old man was admitted with unstable angina, 15 years after saphenous vein graft bypass surgery. Cardiac catheterization demonstrated a large saccular aneurysm arising from the proximal segment of the vein graft to the obtuse marginal artery. Intravascular ultrasound revealed the opening of the aneurysm that measured 15 mm in length. The aneurysm was successfully occluded by deployment of a vein-covered stent.