Background: Previous epidemiological surveys conducted in Japan highlighted problems with conventional approaches to treating chronic musculoskeletal pain. On the basis of prior studies, we initiated the "longitudinal investigation of chronic musculoskeletal pain" in 2010. In our first two reports, we revealed a high prevalence of chronic musculoskeletal pain, low satisfaction with treatment, and reduced quality of life. Those with severe and consistent low back pain had the highest risk of the persisting pain. The risk factors for developing chronic pain also included working in a professional, managerial, or clerical/specialist occupation, being female, having a body mass index !25, currently using alcohol or cigarettes, and having completed an educational level of vocational school or higher. As the final step of the epidemiological survey, the present study examined the effect of chronic musculoskeletal pain on a future decline in activities of daily living (ADL). Methods: A questionnaire was sent to individuals who participated in the research project in 2010. Follow-up research examining loss of basic or instrumental ADL, or certification of long-term care requirements, was conducted in 2013 (n ¼ 4989 subjects). Results: The 3-year follow-up data revealed that chronic musculoskeletal pain was associated with a decline in ADL, even after adjusting for covariables such as age, sex, and smoking (adjusted odds ratio, 1.56; 95% confidential interval, 1.16-2.10). Conclusions: Chronic musculoskeletal pain is associated with future declines in ADL; therefore, relief of the chronic musculoskeletal pain may be important to maintain an active elderly population.