The prevalence of rheumatoid arthritis (RA) and musculoskeletal diseases was determined in a random sample of 1,317 people aged 65, 75, 80, and 85 years. Detailed clinical examinations were carried out in 1989-1990. A total of 6 men and 18 women (1.8% together) fulfilled the 1987 American College of Rheumatology criteria for RA. The prevalence of RA was highest (2.4%) in subjects aged 65 years and tended to decline with age. No RA cases were found in men aged 80 years or more. The prevalence of musculoskeletal diseases, defined as lack of an extremity or restriction of mobility in a joint or the spine, was high, reaching up to 49% in the highest age group.