Objective To investigate the sanitary status of indoor swimming pool water in Fengtai District of Beijing, China, to identify the main problems, and to propose suggestions and measures.

Methods In 2023—2025, stratified sampling was conducted according to the types of places, and water quality monitoring of indoor swimming pools was performed for 52 swimming places in Fengtai District of Beijing. In accordance with the Examination Method for Public places (GB/T 18204), swimming pool water samples were collected and tested for turbidity, pH, free residual chlorine, urea, total bacterial count, and coliform.

Results In 2023—2025, a total of 156 water samples were collected from 15 hotel swimming pools and 37 swimming pools from fitness and entertainment venues, with a qualified rate of 16.67%. The qualified rates of samples in 2023—2025 were 6.25%, 16.67%, and 25.93%, respectively, with a significant difference across years (χ²=7.08, P=0.029). The qualified rates of samples were 31.11% in hotel swimming pools and 10.81% in swimming pools from fitness and entertainment venues, with a significant difference between the two types of swimming pools (χ²=9.50, P=0.002). The qualified rates of free residual chlorine, pH, urea, coliform, total bacterial count, and turbidity were 58.33%, 59.62%, 66.67%, 88.46%, 91.67%, and 98.08%, respectively, with a significant difference between these indicators (χ²=136.93, P < 0.001).

Conclusion There are certain improvements in the water quality of indoor swimming pools in Fengtai District of Beijing in 2023—2025, but there are still problems such as an extremely low or high level of free residual chlorine, excessive urea, coliform pollution, and excessive total bacterial count, which poses certain health risks. It is recommended to strengthen hygiene supervision and monitoring of indoor swimming pools in Fengtai district in the future.