Acute dissection of the ascending aorta as a late complication of coronary artery bypass grafting has been rarely reported. We report a case of a 61 year-old man in whom acute dissection of the ascending aorta developed 2 years after coronary artery bypass grafting. The ascending aorta was replaced with a Dacron graft, and an island of the aortic wall, on which previous proximal anastomoses had been placed, was implanted into the Dacron graft successfully.