A comprehensive population study of women aged 44-46 was carried out in Göteborg, Sweden in 1974-75. The mean erythrocyte sedimentation rate (ESR) and the rate of high ESR values (defined as ESR greater than or equal to 30 mm) were higher in women with manifestations of joint diseases than in other women, the differences being statistically significant for women with swollen or deformed finger joints and symptoms from the wrists. Women with manifestations of active joint disease at the time of the examination had even higher ESR values, the differences being statistically significant also for women with symptoms from the finger joints. High ESR values were more common in women with a positive serological test for rheumatoid factor and joint manifestations indicating arthritis and osteoarthrosis. The "arthritis" and "osteoarthrosis" groups each included about one-third of the subjects with rheumatoid factor. It is concluded that although ESR values are moderately increased in subjects with different manifestations of joint disease, the vast majority of such subjects have ESR values less than 30 mm.