Traumatic aneurysm of the ascending aorta is a rare event. This case describes a patient with such an aneurysm, resulting from injuries received in a motorcycle accident. The patient was admitted to the emergency room of a local hospital complaining of chest pain, and was subsequently referred to our institution. On admission, a chest x-ray showed mediastinal widening. Computed tomography and aortography revealed an ascending aortic aneurysm and contusion of the upper lobe of the right lung. Due to concerns about bleeding from the lung contusion, surgery was delayed for one week. During surgery, intimal tears were detected at two sites in the ascending aorta. The wall of the ascending aorta was subsequently resected and a prosthetic graft inserted. The postoperative period was uneventful and a postoperative aortogram showed that the graft had molded well.