Blunt traumatic aortic injury (BAI) is a condition associated with high morbidity and mortality. Nonoperative management is advocated for patients with minimal aortic injury (grade I), but for grade II-IV, BAI operative repair remains the standard of care as recommended by the Society for Vascular Surgery (SVS). The SVS classifies blunt traumatic aortic pseudoaneurysms as grade III injuries and recommends repair using thoracic endovascular aortic repair (TEVAR). We have observed significant variability among severity of grade III BAI and have adopted a management strategy consisting of immediate TEVAR (<24 hours), delayed TEVAR (>24 hours), and selective nonoperative approaches for the management of these injuries. We therefore evaluated outcomes with these approaches in comparison with immediate TEVAR. We retrospectively identified all BAI presenting to an academic level I trauma center over a 15-year period (2000-2014). Computed tomography cross-sectional images were reviewed by a radiologist and graded according to SVS guidelines (grade I-IV). Pseudoaneurysm size was measured in three dimensions. Demographics, injury severity score (ISS), and outcomes were recorded. Patients were selected for operative intervention based on the size and morphology of the pseudoaneurysm, coexisting burden of traumatic injury, age, and comorbidities, at the discretion of the vascular surgeon. Patients were grouped according to management strategy: immediate TEVAR (i-TEVAR, ≤24 hours of admission), delayed TEVAR (d-TEVAR, >24 hours from admission), and nonoperative management (nonop). Outcomes in these groups were compared. Primary outcome measures were overall mortality and aortic-related mortality (death due to aortic injury). We identified 153 patients with grade III BAI. Mean age was 39.3 years, and mean ISS was 38.6. Patients were excluded if they did not have meaningful possibility of recovery from traumatic injuries (n = 18) or if they underwent open repair (n = 48). The remaining patients were grouped as follows: i-TEVAR (n = 32), d-TEVAR (n = 16), and nonop (n = 37). ISS was similar in all three groups (P = NS). TEVAR was performed a median of 5 days and a mean of 30 days after injury in the d-TEVAR group. Overall mortality was 15.6% in the i-TEVAR group at 3.1 years’ mean follow-up, 6% in the d-TEVAR group at 1.5 years, and 18.9% in the nonop group at 1.7 years (P = NS). Aortic-related mortality was 6% for i-TEVAR, 0% for d-TEVAR, and 3% in the nonoperative group (P = NS). Mean maximum pseudoaneurysm dimension was 33 mm for i-TEVAR, 33 mm for d-TEVAR, and 23 mm in the nonop group (P = .0003 vs i-TEVAR, P = .005 vs d-TEVAR). Patients presenting with grade III BAI may be safely managed with a delayed operative or nonoperative approach in selected circumstances with minimal associated mortality. Delayed TEVAR provides a window of opportunity for selection of patients for TEVAR who do not succumb to their other traumatic injuries. Nonoperative management may be appropriate for patients presenting with smaller pseudoaneurysms, as we did not observe rupture in pseudoaneurysms measuring ≤31 mm in maximum diameter in patients managed nonoperatively. Mortality in all these groups was high, primarily as a result of other traumatic injuries, and therefore, appropriate selection of patients for TEVAR must rely on sound clinical judgement.