An 82-year-old man was taken to a local clinic following the occurrence of syncope. Chest roentgenography and computed tomography (CT) findings led to a suspicion of a ruptured aortic aneurysm, and the patient was immediately transferred to our hospital. Upon admission, his consciousness was clear and blood pressure was 74/47mmHg. Enhanced chest CT images demonstrated pericardial effusion and a saccular aneurysm with a maximum diameter of 5cm, which was associated with a thrombus in the distal aortic arch. An emergency operation was performed under a diagnosis of a ruptured distal aortic arch aneurysm and hemorrhagic cardiac tamponade. During the procedure, a hole was found in the lesser curvature of the aneurysm, which had directly ruptured into the pericardial space, and a graft replacement of the aortic arch was performed using selective cerebral perfusion. The patient was discharged 19 days after surgery without any postoperative complications.