Abstract.[Purpose] The purpose of this study was to investigate whether ten weeks of aquatic therapy exercise would increase low back muscle strength and reduce low back pain in 19 elderly subjects.[Subjects] Nineteen low back disorder patients were randomly assigned to one of two groups: an aquatic therapy exercise group (n=9), and a control group (n=10).[Methods] The aquatic therapy group participated five times a week for ten weeks in an aquatic exercise designed to strengthen the low back muscles. Data collection was done using a Cybex-770 system.[Results] The results show that the aquatic exercise significantly reduced visual analog scale pain by 52.1%. Significant improvements in low back muscle strength were found in the aquatic therapy group on peak torque of flexor in 180°/sec by 48.31% and on peak torque of extensor in 180°/sec by 152.85% . [Conclusion] Based on the results, we conclude that the ten weeks of aquatic therapy exercise can enhance low back muscle strength and reduce low back pain in elderly women.