Although a bicuspid aortic valve (BAV) is known to be associated with progressive ascending aortic dilatation, the fate of the residual aorta after aortic valve and ascending aorta surgery is unknown. We reviewed surgical outcomes and explored serial changes in the size of the sinus of Valsalva (SOV) and distal ascending aorta (DAAo) in 89 patients with a BAV undergoing aortic valve replacement (AVR) and graft replacement (GR) of the ascending aorta. We retrospectively examined patients who underwent AVR and GR of the ascending aorta for BAV-and related disease and thoracic aortic dilatation at our institution between January 2009 and December 2018. Patients who underwent AVR alone or required intervention for the aortic root and aortic arch and patients with connective tissue diseases were excluded. Aortic diameters were examined using computed tomography (CT). Late CT more than 1 year after surgery was performed in 69 patients (78%) with a mean follow-up of 4.9±2.8 years. The surgical indication for aortic valve etiology was stenosis in 61 patients (69%), regurgitation in 10 (11%), and mixed in 18 (20%). Preoperative maximum short diameters of the ascending aorta, SOV, and DAAo were 47.3±4.7, 36.0±5.2, and 37.2±3.6 mm, respectively. The diameter of the SOV increased non-significantly by 0.08±0.45 mm per year [95% confidence interval (CI): -0.12 to 0.11, P=0.150], while that of the DAAo increased significantly by 0.11±0.40 mm per year (95% CI: 0.02-0.21, P=0.005). One patient required reoperation 6 years postoperatively due to a pseudo-aneurysm at the proximal anastomotic site. No patient required reoperation due to progressive dilatation of the residual aorta. According to the Kaplan-Meier analysis, the long-term survival rates were 98.9%, 98.9%, and 92.7% at 1, 5, and 10 years postoperatively, respectively. Rapid dilatation of the residual aorta rarely occurred in patients with a BAV who underwent AVR and GR of the ascending aorta in the mid-term follow-up. For selected patients with a surgical indication for ascending aortic dilatation, simple AVR and GR of the ascending aorta may be sufficient surgical options.