In the 5 yr period ending in Oct. 1975, 31 consecutive patients with traumatic rupture of the thoracic aorta underwent surgery. All cases were confirmed by preoperative aortogram. Rupture was confined to 1 or more sites in the descending thoracic aorta at or distal to the origin of the left subclavian artery. The mean age was 26 yr. Operation was done within an average of 18 h after injury. Significant nonthoracic injuries were present in every case. Six patients with positive findings on peritoneal lavage underwent exploratory laparotomy prior to thoracotomy because of shock. Surgical repair was done by use of left heart bypass in 2 cases (1 death), a passive aorta-aorta shunt in 23 cases (5 deaths), and without shunt or bypass in 6 cases (no deaths). An end-to-end tubular Dacron graft was used to reconstruct the aorta in all but 1 patient. Over-all survival rate was 25 of 31 patients (81%). Paraplegia developed in 1 patient and renal failure in 3 patients (2 deaths) in the aorta-aorta shunt group. Hypertension was present in 18 (72%) of the survivors. Palsy of the left recurrent laryngeal nerve persisted in 8 (32%) of the survivors. Two of the deaths were related to technical problems of the shunting procedure and 2 to intrapleural exsanguination before proximal aortic control was achieved. Complications and blood loss were reduced in the group with no shunt. The rigorous aortographic search for ruptured thoracic aortas in trauma patients with widened mediastinum was supported. Once experience was gained with shunting techniques, tears of the descending thoracic aorta may be safely repaired without shunt if done expeditiously.