PURPOSE: Japan's aging population poses challenges for balancing healthcare demands and workforce supply. The aim of this study was to project the future demand for major non-cancerous gastrointestinal surgeries such as cholecystectomy, inguinal hernia repair, and appendectomy up until 2050 and examine the impact of a shrinking working-age population on surgical workforce needs. METHODS: We used data from the National Database of Health Insurance Claims and Specific Health Checkups of Japan Open Data (2018-2022) and population projections to calculate age- and sex-specific procedure rates. These rates were applied to population forecasts for 2030, 2040, and 2050 under high, low, and average demand scenarios. Working-age population (15-65 years) trends were included for comparison. RESULTS: The projected demand for appendectomy, most common in people aged 20-39, is expected to decrease by 16.6% by 2050, whereas cholecystectomy and inguinal hernia repair demand, concentrated in people aged 60 and above, are projected to decrease by 5.8% and 7.1%, respectively. The working-age population is anticipated to decline by 25.3%, potentially posing significant challenges to maintaining an adequate surgical workforce. CONCLUSIONS: While the absolute number of gastrointestinal surgeries is projected to decrease, Japan faces substantial demographic changes that may impact surgical workforce capacity. Strategic workforce planning is essential to address these demographic challenges.