Objectives: During the last decade, endovascular repair (EV) has replaced open surgical repair (OSR) as the preferred method of treatment of blunt traumatic thoracic aortic injuries (BTAIs) at many trauma centers. This has resulted in reductions in mortality, length of stay, and major complications, including paraplegia, with the added expense of the initial endograft, subsequent surveillance, and reinterventions. The purpose of this study was to conduct an economic evaluation comparing these two methods of repair. Methods: We performed an economic comparison of EV and OSR for the treatment of BTAI using a decision tree analysis with transition points derived from our institution's experience and through a review of the literature. Over a 15-year period (1991-2006), 28 patients with BTAI were treated at our center (15 EV, 13 OSR). Costs were obtained from our hospital's case costing center, the Ontario Case Costing Initiative, Ontario's Drug Benefit Formulary, and Ontario's Schedule of Benefits for physician costs. Our center's results were then combined with those from the literature to arrive at an economic model. Results: These combined results revealed that EV, when compared to OSR, resulted in decreased early mortality (7.2% vs 22.5%), decreased composite outcome of mortality and paraplegia (7.7% vs 27.6%) and decreased composite outcome of mortality and major complication (42.5% vs 69.8%). Patients undergoing EV also had shorter intensive care unit stays (12.2 vs 15.3 days), total hospital length of stays (22.5 vs 28.6 days), and ventilator days (8.0 vs 9.2 days). Additionally, patients undergoing EV had decreased total 1-year costs compared with OSR ($70,442 vs $72,833). Conclusions: EV repair of BTAIs offers a survival advantage as well as a reduction in major morbidity, including paraplegia, compared with OSR, and results in a reduction in costs at 1 year. As a result, from the cost-effectiveness point of view, EV is the DOMINANT therapy over OSR for these injuries.