The durability of root repair for acute type A aortic dissection is not well studied in the context of aortic insufficiency and stability of the sinuses of Valsalva. We compared clinical and functional outcomes in patients undergoing root repair and replacement for acute type A aortic dissection. Of 716 patients undergoing surgery for acute type A aortic dissection, 585 (81.7%) underwent root repair and 131 (18.3%) underwent root replacement. Survival, cumulative incidence of reoperation, aortic insufficiency, and sinuses of Valsalva dilation were compared between the 2 groups. Survival at 1, 5, and 10 years was 84.1% versus 77.3%, 70.8% versus 69.2%, 57.6% versus 58.0% in the root repair and replacement groups, respectively (P = .69). Cumulative incidence of reoperation at 1, 5, and 10 years was 0.0% versus 0.8%, 1.4% versus 3.8%, and 3.4% versus 8.6% in the root repair and root replacement groups, respectively (P = .011). Multivariable Cox regression identified sinuses of Valsalva diameter 45 mm or more as a risk factor for proximal aortic reoperation (hazard ratio, 9.06; 95% confidence interval, 1.26-65.24). In a repeated-measures, linear, mixed-effects model, root replacement was associated with smaller follow-up of sinuses of Valsalva dimensions (β = -0.66, P < .001). In an ordinal longitudinal mixed model, root replacement was associated with lower severity of postoperative aortic insufficiency (β = -3.10, P < .001). Survival is similar, but the incidence of aortic insufficiency and root dilation may be greater after root repair compared with root replacement for acute type A aortic dissection. Copyright © 2020 The American Association for Thoracic Surgery. Published by Elsevier Inc. All rights reserved.