A 33-year-old male who had received Bentall's operation 10 years ago was admitted to our hospital with severe chest pain. The pseudoaneurysm at the right coronary ostium was observed on angiography and CT scan. He underwent the repair of the anastomosis between the graft and the right coronary ostium under extracorporeal circulation. Although he was discharged from the hospital asymptomatically, he was again admitted to our hospital with severe chest pain and back pain 4 months after re-operation. Aneurysmal formation of the ascending aorta due to blood leakage from the distal anastomotic suture line was observed and the graft was compressed by hematoma on angiography and CT scan. He underwent re-operation of the distal anastomosis of the graft, and could be discharged from the hospital uneventfully.