Objectives: To further assess the early and mid-term outcomes of thoracic endovascular aortic repair (TEVAR) in patients with acute uncomplicated type B aortic dissection (TBAD) compared with those receiving best medical treatment (BMT). Methods: Between February 2008 and March 2018, 357 consecutive patients with acute uncomplicated TBAD were retrospectively analyzed. Among them, 191 patients underwent TEVAR, and 166 received BMT. After propensity score matching, we obtained 145 matched pairs for analysis. Results: In the matched population, the 30-day mortality between the TEVAR group and the BMT group showed no statistically significant difference, whereas the early adverse events rates in the TEVAR group were significantly greater than that of the BMT group (P ¼ .003). Freedom from all-cause mortality in the TEVAR group was significantly greater than that of the BMT group (TEVAR: 91.9% at 5 years, BMT: 82.2% at 5 years, P ¼ .028). Freedom from aortic-related mortality in the TEVAR group was significantly greater than that of the BMT group (TEVAR: 94.1% at 5 years, BMT: 86.1% at 5 years, P ¼ .044). Multivariable Cox-hazard regression analysis demonstrated that the older age (hazard ratio [HR], 1.04; 95% confidence interval [CI], 1.01-1.08, P ¼ .013), BMT (HR, 2.33; 95% CI, 1.08-5.05, P ¼ .032), and the distance between the primary entry tear and the left subclavian artery<2.0 cm (HR, 2.30; 95% CI, 1.06-4.99, P ¼ .035) were the significant risk factors for all-cause death. Given death as a competing factor, the cumulative incidence of rupture in the BMT group was significantly greater than that of the TEVAR group (BMT: 13.7% at 5 years, TEVAR: 5.1% at 5 years, P ¼ .024). Conclusions: Despite more complications in the early stage, TEVAR was associated with decreased risk of late death and had fewer late aortic ruptures compared with BMT in patients with acute uncomplicated TBAD. Therefore, TEVAR may be considered as the first option to improve the late outcomes in these patients.