We compared the long-term outcomes and difference in dilatation rates of the ascending aorta after aortic valve (AV) replacement (AVR) between bicuspid and tricuspid AV patients, and evaluated risk factors associated with ascending aorta dilatation and aortic events during the follow-up. Of 1,127 patients who underwent AVR from 1995 to 2015, 259 patients with a dilated ascending aorta (≥40 mm in diameter) were included. The patients were divided into those with bicuspid (group bicuspid aortic valve [BAV], n = 105) and with tricuspid (group tricuspid aortic valve [TAV], n = 154) AV, and a propensity score-matched analysis was performed to match 98 patients in each group. The differences in the dilation rate of the ascending aorta and long-term outcomes were analyzed. Risk factors for ascending aorta dilatation, mortality, and aortic events were identified. Follow-up was completed in 100% of patients with a median follow-up duration of 106.1 [68.8, 163.0] months. The early clinical outcomes and dilation rate of the ascending aorta were similar between the groups. Overall survivals up to 15 years postoperatively were similar between groups BAV and TAV (p = 0.223). Aortic events occurred in 6 patients (groups BAV vs TAV, 2 vs 4;p = 0.678). Preoperative ascending aorta diameter showed a linear relationship with the dilatation rate of ascending aorta (p <0.001) and was related to progressive aortic dilatation and aortic events (odds ratio: 1.25, p <0.001 and hazard ratio = 1.56, p <0.001, respectively). In conclusion, the long-term outcomes and ascending aorta dilatation rate were similar between the BAV and TAV patients up to 15 years after AVR. Bicuspid AV was not a risk factor of mortality or aortic events.