A 69-year-old man with coronary artery disease associated with abdominal aortic aneurysm underwent a one-stage operation utilizing a low-flow cardiopulmonary bypass. Ordinary cardiopulmonary bypass was abandoned as a result of severe atheromatous finding in the entire aorta. However, coronary artery bypass grafting without cardiopulmonary bypass was hazardous as a result of heart enlargement and deteriorating function. Therefore, the abdominal aortic aneurysm was first replaced with a bifurcated graft. Coronary artery bypass grafting with two arterial grafts was then performed successfully on the beating heart with the support of a low-flow cardiopulmonary bypass connected to the bifurcated graft.