Back pain due to vertebral collapse is the main symptom of postmenopausal osteoporosis. The clinical picture in these crush fractures varies, depending on the type and the location of fracture, but in general, a new vertebral crush fracture gives rise to severe pain that immobilizes the patient and necessitates bedrest. In this double-blind controlled clinical trial, 56 patients who had recently (within the last 3 days) suffered an osteoporotic vertebral fracture were hospitalized for a period of 14 days. Salmon calcitonin (100 IU) or placebo injections were given daily. Pain was rated daily on a 10-point scale by the same observers. Blood and urinary parameters were also evaluated. The results showed a significant (P<0.001) difference in pain intensity between the calcitonin group and the placebo group. This beneficial effect was generally apparent from the second day of treatment onward, and over the following 2 weeks, the patients were able to sit and stand, and gradually started to walk again. A significant decrease in urinary hydroxyproline and urinary calcium was also noted in the calcitonin group. It is concluded that calcitonin exerts a beneficial effect on back pain following a vertebral crush fracture.