The effect of intranasal salmon calcitonin on pain, erosion progression, and bone loss in 40 women with rheumatoid arthritis was investigated. The study design was double blind, placebo controlled for the first four months and open for the next 36 months, allowing for cross over to active drug treatment or to the control group. Morning stiffness was reduced in the group treated with salmon calcitonin after two and four months. After an average follow up of 28 months no significant effect on erosion progression was observed using the Larsen score. The mean (SD) monthly progressions in the Larsen score in the calcitonin and control groups were 0.21 (0.22) and 0.23 (0.28) respectively. The bone mineral density was evaluated in the forearm and spine. During the 12 months of follow up the control group lost bone at a rate of 2%/year at the spine and 4.8%/year at the radius distal third. In contrast, the group receiving nasal calcitonin gained 1% in bone mineral density at the lumbar spine and no loss at the radius distal third. The increase in bone density at the spine in the calcitonin group was not sustained and a loss of 1.8%/year was observed in the second year. The difference with the placebo group remained significant.