Abdominal aortic aneurysm (AAA) is commonly associated with coronary artery disease (CAD). Simultaneous coronary artery bypass grafting (CABG) with cardiopulmonary bypass (CPB) under cardiac arrest and AAA repair may be considerably invasive. Recently CABG under the beating heart without CPB has been reported as a less invasive method. We report the combined operation of CABG on a beating heart and AAA repair for AAA patients with CAD, and compare it with a separate operation. A retrospective review of the records of consecutive patients who underwent elective combined procedure or single operation for CABG on a beating heart and/or repair of the AAA between May 1999 and October 2001 was carried out. Ten patients underwent combined procedures. A single operation, CABG on a beating heart or repair of AAA, were performed in 27 or 19 patients. There were no significant differences with regard to intraoperative blood loss, transfusion and postoperative intubation time among the three groups. There was no operative mortality for any of the three groups. All cases were discharged without severe complications and with patent coronary bypass grafts. There was a decrease in mean total hospital costs for the combined operation group compared with the CABG group plus AAA repair group (3.34 million versus 5.87 million yen). Combined CABG on a beating heart and AAA repair on a one-step approach appears to be a safe and useful therapeutic strategy for AAA patients with CAD.