Two young adult patients with brachiocephalic avulsion due to blunt trauma are reported. Both of them were brought to the emergency room of St. Marianna University Hospital with the blunt chest trauma and lung contusion due to the traffic accident. A widening of the superior mediastinum and mediastinal hematoma surrounding the major branches of the aortic arch were demonstrated on chest roentgenogram and contrast enhanced CT scan, however, these evidences were not valuable for the diagnosis. Aortogram revealed an aneurysmal dilatation at the origin of the brachiocephalic artery in the first case and at its distal portion in the second case. Emergency operation was performed under the simple cross clamp of the brachiocephalic artery without any adjunct means. In the first case, 10 mm knitted Dacron graft was interposed between the ascending aorta and distal segment of the brachiocephalic artery. In the second case, the brachiocephalic artery was replaced with 10 mm knitted Dacron graft. The postoperative course was uneventful and no neurological deficit was noted in these cases.