We investigated changes in quality of life (QOL), including pain, in Japanese women aged ≥ 55 years who were diagnosed as having osteoporosis at 265 centers across Japan and treated continuously with once-weekly bisphosphonates for 24 months. In 2650 evaluable patients, a significant improvement in QOL was observed from 3 months after enrollment onward and maintained throughout the 2-year observation period. A significant improvement in scores was observed for all domains of the Euro QOL 5 Dimension (EQ-5D), and the "pain", "health perception", and "posture, figure" domains of the Japanese Osteoporosis QOL Questionnaire (JOQOL). Factors identified as significantly contributing to QOL change were "fractures within the year before enrollment", "presence of spondylosis deformans", "presence of osteoarthritis", "use of activated vitamin D3", and "age" based on the JOQOL, and "presence of spondylosis deformans", "use of activated vitamin D3", and "age" based on the EQ-5D. The results suggested that the patients' perception of treatment effects, such as improvement in pain, contributes to treatment continuation. Osteoporosis patients should be informed that continuous treatment with once-weekly bisphosphonates can lead to a significant improvement in QOL regardless of concomitant locomotor diseases, to encourage them to remain on treatment. In conclusion, continuous bisphosphonate treatment improved the QOL even in patients with locomotor diseases, and the concomitant use of activated vitamin D3 may also facilitate further improvement in QOL.