Abstract Background Transcatheter aortic valve implantation (TAVI) is less invasive than surgical aortic valve replacement and is becoming increasingly popular worldwide, particularly among patients with aortic valve stenosis (AS) due to aging. However, regional differences are expected to exist not only between countries but also within a single country. Reports from Western countries indicate the presence of regional differences in TAVI and the reasons for these differences, which include differences in medical infrastructure, economic resources, health insurance systems and policies, geographic factors, and availability of specialized medical personnel. TAVI is expensive, but in Japan, the economic aspect is relatively unimportant due to the high-cost medical assistance system. Furthermore, there is little socioeconomic disparity between regions. In such a society, we have reported that the number of specialists and resources for PCI can explain regional differences in ablation and endovascular treatment (EVT). However, unlike those other cardiovascular procedures, there are specific requirements for facilities to perform TAVI, such as the number of transesophageal echocardiographies, as well as cardiologists and cardiovascular surgeons, and the equipment itself, such as hybrid operating rooms. We examined how these facility requirements, which are thought to be controlled by the government, are related to regional differences in TAVI implementation. Methods and Results We used the Japanese Ministry of Health, Labour and Welfare national database to determine the rate of TAVI for patients with AS performed per 100,000 population aged ≥40 years in all 47 prefectures in 2022. A linear regression model was developed to assess factors contributing to the regional medical supply, including the rates of PCI per 100,000 population aged ≥40 years and the numbers of cardiologists, cardiovascular surgeons, cardiovascular intervention and therapy training facilities, cardiovascular surgery base facilities, and TAVI facilities. The numbers in the highest and lowest regions were 26.6 and 3.9 (a 6.8-fold difference) for TAVI number. The number of TAVI facilities contributed most significantly to the TAVI volumes (P = 0.0105), while the rates of PCI and other factors did not contribute significantly. The number of TAVI facilities was positively correlated with the number of transesophageal echocardiographies the most (r = 0.353). Conclusion This study revealed large regional variations in TAVI volumes in Japan, of which administrative facility standards were a major determinant.