The authors examined the degree of bone loss by single photon osteodensitometry in 72 patients with rheumatoid arthritis (RA). A control group was set up consisting of osteoarthritis patients of the same age and gender. As a result of the osteodensitometrical examination osteopenia was observed in 22-, osteoporosis in 37- and normal density in 14 rheumatoid arthritis patients. These results showed considerable difference compared to the density results of the control group (n = 72) (p < 0.001). They also analysed the role of risk factors affecting bone loss in three groups of rheumatoid arthritis patients, with osteoporosis, osteopenia and with normal density results. As risk factors the duration of the rheumatoid arthritis, the duration of the postmenopause, the age, the cumulative doses of steroid and the activity of rheumatoid arthritis were mentioned. Among risk factors the duration of the rheumatoid arthritis, the age, the duration of the postmenopause and the Steinbrocker phase classification correlated with the osteodensitometrical results. At the same time no correlation has been observed in relation to the cumulative doses of steroid and the Ritchie joint index.