Background: We report the usefulness of emergency thoracic endovascular aortic repair (TEVAR) for complicated acute type III aortic dissection. Methods: We studied a total of 20 patients with complications secondary to acute aortic dissection who were treated by emergency TEVAR from 2003 to 2010. Although fenestrated or non-fenestrated hand-made stent grafts (SG) were used in most cases, commercial SG have also been used, if anatomically suitable, since 2008. Results: The mean age was 69.7 years (range, 39-82) and there were 16 men in this study (80%). The types of aortic dissection were IIIa in 7 cases, IIIb in 8 and IIIbR in 5. Aortic dissection-related complications were rupture in 10 cases (50%), impending rupture in 5 (25%) and visceral or leg ischemia in 6, including 1 combined with rupture. A 79- and an 82-year-old patient with ruptured type IIIbR and IIIb aortic dissection, respectively, died due to re-rupture. The early mortality rate was 10%. Although 1 patient (5%) with left subclavian arterial dissection suffered cerebellar infarction following TEVAR, there were no cases of spinal cord ischemia as a complication of TEVAR. The thrombo-occlusion rate of type-IIIa false lumens was satisfactory (86%) in the follow-up period. The overall survival rate, aorta-related death-free rate and aorta-related event-free rate at 5 years after TEVAR were 73.5%, 100% and 84.4%, respectively. Conclusion: Emergency TEVAR was very useful for complicated acute aortic dissection. However, further investigation is necessary to more precisely define its indications for ruptured type IIIb aortic dissection.