The Danish Health and Morbidity Survey of 1986-87 demonstrates a high prevalence of musculoskeletal disorders in the population over 15 years of age. The point-prevalence for long-standing illnesses of the musculoskeletal system was 13 percent. Half of the respondents had had pain during the last 2 weeks. Back disorder was the specific disease that was most frequent. Diseases and symptoms of the musculoskeletal system were frequent in the age groups over 44 years old, and occurred more often in women than in men. Back disorders were reported more often by blue-collar workers and self-employed persons than by white-collar workers. The study has contributed to an action program in the Danish government program on health.