Pseudoaneurysms of the ascending aorta, which are rare and life-threatening complications in cardiovascular surgeries, can be caused by the Bentall procedure. We describe a 44-year-old woman, who had a medical history of acute aortic dissection (Type A) and the Bentall procedure and was admitted because of exertional dyspnea, edema of the lower extremities, ascites, and holosystolic murmur in the left lower sternal border. Preoperative echocardiography revealed a pseudoaneurysm of the ascending aorta and fistulization of the pseudoaneurysm to the right atrium. Multi-slice computed tomographic scan also showed a large pseudoaneurysm of the ascending aorta around the tube graft. The patient underwent surgery, during which the pseudoaneurysm was resected, the ostium of the right coronary artery was reimplanted, and the orifice of the right atrial fistula was sutured. Intraoperative transesophageal echocardiography revealed the perfect result of the surgery. The patient was discharged uneventfully.