Background: The aim of our study was to provide real-world data on outcomes for elderly Taiwanese patients who underwent transcatheter aortic valve replacement or surgical aortic valve replacement in different risk groups. Methods: From March 2011 through December 2021, 177 patients with severe aortic stenosis who were ≥70 years old and had undergone TAVI (transcatheter aortic valve implantation) or SAVR (surgical aortic valve replacement) in a single center were divided by STS score (<4%, 4–8% and >8%) into three different groups. Then, we compared their clinical characteristics, operative complications, and all-cause mortality. Results: In all risk groups, there were no significant differences in in-hospital mortality, or 1-year and 5-year mortality between patients in the TAVI and SAVR groups. In all risk groups, patients in the TAVI group had shorter hospital stay and higher rate of paravalvular leakage than the SAVR group. After univariate analysis, BMI (body mass index) < 20 was a risk factor for higher 1-year and 5-year mortality. In the multivariate analysis, acute kidney injury was an independent factor for predicting worse outcomes in terms of 1-year and 5-year mortality. Conclusions: Taiwan elderly patients in all risk groups did not have significant differences in mortality rates between the TAVI and the SAVR group. However, the TAVI group had shorter hospital stay and higher rate of paravalvular leakage in all risk groups.