We report a case of aortic arch rupture due to blunt chest trauma. The patient was a 66-year-old man who was driving a motorcycle and collided with a parked car. The chest roentogenogram showed mediastinal widening and computed tomography showed hematoma of the mediastinum and intimal tear of the aortic arch. As his hemodynamic state was stable, he underwent aortography which demonstrated pseudoaneurysm of the aortic arch. An emergency operation was performed under cardiopulmonary bypass with selective cerebral perfusion. The intimal and medial tear of the aortic arch and left common carotid artery were replaced with grafts and his postoperative course was uneventful. Traumatic aortic rupture is frequent in the descending aorta but aortic arch injury is rare. Immediate diagnosis and surgical repair are necessary in such cases.