Reflex sympathetic dystrophy syndrome is a difficult condition to treat. Many modalities have been proposed, all of them being clinically effective but whose efficacy is often difficult to assess, and has not been properly compared. A regimen of physical therapy (pressure therapy, antalgic electrotherapy and exercise therapy) with or without calcitonin was investigated in 24 patients randomly assigned to 2 groups, one given physical therapy alone (Group I) and the other physical therapy plus salmon calcitonin 100 MRC units daily for 3 weeks (Group II). Efficacy assessment was based on clinical (pain, oedema and movement in the affected parts), biochemical (blood and urinary phosphorus and calcium levels, plasma 25-OH-D, plasma parathyroid hormone (PTH), creatinin, alkaline phosphatases and urinary hydroxyproline) and scintigraphic parameters, as well as on the patient's ability to resume working. There was significant improvement in pain in the Group II patients after one week of treatment. As a result the authors advocate the use of calcitonin in addition to physical therapy in reflex sympathetic dystrophy syndrome - and even of calcitonin alone where physical therapy is not possible.