We report a case of calcific aortic stenosis in a 79-year-old man who had undergone aortocoronary bypass. Since ordinary valve replacement was problematic because of severe annular calcification, a small annular diameter, and three patent vein grafts, we performed ultrasonic aortic valve decalcification. As a result, the pressure gradient across the aortic valve decreased from 100 mmHg to 25 mmHg, and the patient is doing well to date at two years after the operation. Although long-term results of ultrasonic aortic valve decalcification are still undetermined, it appears worth considering in cases in which ordinary valve replacement could be extremely difficult.