Objective: Sex-based differences in outcomes for patients undergoing degenerative aortic aneurysm repair have been well described, with female patients having worse early and long-term outcomes compared with male patients. However, differences between men and women after thoracic endovascular aortic repair (TEVAR) of acute complicated type B aortic dissection (TBAD) have not been well characterized. Therefore, the objective of the present study was to assess the sex-based differences in clinical presentation, time to repair, morbidity, and mortality for patients undergoing TEVAR for TBAD. Methods: All TEVAR procedures performed for acute complicated TBAD from a single academic medical center from August 2005 to January 2020 were analyzed. The clinical presentation, time to repair, and outcomes were compared by sex. The primary outcome was 30-day mortality. The secondary outcomes were in-hospital complications, reintervention, aorta-related death, and out of hospital survival. The predictors of mortality, including sex, were determined using multivariable logistic regression. Results: A total of 159 patients (38 women [24%]) were included in the analysis. No sex-based differences were found in clinical presentation or comorbidity prevalence between the female and male patients. The female patients had had a longer overall time from initial symptom onset to TEVAR (female patients: median, 3.5 days [interquartile range (IQR), 1-10 days]; male patients: median, 1 day [IQR, 1-3]; P = .007). However, no differences were found in the time to repair after admission to the academic medical center (female patients: median, 1 day [IQR, 0-5 days]; male patients: median, 1 day [IQR, 0-3]; P = .176). No differences were found in the unadjusted aortic-related, in-hospital, or 30-day death between the female and male patients. Similarly, the risk-adjusted analysis revealed that sex was not associated with adverse outcomes. The 1-and 5-year freedom from aortic-related mortality were 82% +/- 4% and 87% +/- 6% and 79% +/- 4% and 80% +/- 8% for the men and women, respectively. Conclusions: We found no differences between the female and male patients with acute complicated TBAD who had undergone TEVAR in the clinical presentation or comorbidities. The female patients had undergone TEVAR after a longer duration of symptoms, but this was not associated with sex-based differences in early or late morbidity or mortality.