Abstract Objectives A hemiarch reconstruction, using deep hypothermic circulatory arrest, is the conventional approach for proximal aortic arch reconstruction, but it carries risks of neurologic events and coagulopathy. The addition of a hemiarch reconstruction to an aortic root replacement may prevent future aortic arch pathology. Outcomes of this approach at a tertiary care institution were examined to determine whether the addition of a hemiarch reconstruction to an aortic root replacement conferred any additional risk. Methods A total of 384 patients underwent an aortic root replacement between April 2004 and June 2012. Of them, 177 (46%) had hemiarch replacement. Propensity score matching yielded 133 pairs of patients receiving hemiarch and non-hemiarch. Results Sinus segment diameter was similar between groups; ascending aortic diameter was greater in the hemiarch group (median 50 vs 44 mm; P  < .001). The hemiarch group had longer perfusion (median 186 vs 120.5 minutes; P  < .001) and crossclamp times (median 140 vs 104 minutes; P  < .001); median circulatory arrest was 13 minutes. There was no difference, hemiarch versus no hemiarch, in 30-day mortality (3.0% vs 1.5%; P  = .41), stroke (2.3% vs 4.5%; P  = .31), reoperation for bleeding (11% vs 10%; P  = .84), or overall survival (5-year 88.0% 95% confidence interval, 81.9-94.0 vs 91.4% 95% confidence interval, 85.8-96.9, P  = .24). Conclusions In this series, aortic root replacement ± hemiarch reconstruction had low mortality. Addition of hemiarch replacement extended perfusion times but not at the expense of safety. Hemiarch reconstruction should be performed when the aortic root aneurysm extends into the distal ascending aorta.