The aim of the study was to evaluate the efficacy of half-year treatment of bone mineral disturbances with calcitonin in the patients with multiple myeloma. Thirty five patients (11 men and 24 women) were examined. They were treated among other with prednisone. Nineteen patients (15 patients with normal bone mineral density of lumbar spine and femoral neck and 4 with low bone mineral density who could not be treated with calcitonin) were treated only with chemotherapy. Other 16 patients with low bone mineral density have received also calcitonin (100 units subcutaneous daily) with vitamin D3 and calcium carbonate. Bone mineral density was evaluated with dual energy X-ray absorptiometry in lumbar spine and femoral neck. After treatment with calcitonin there was more pronounced influence on bone mineral density in lumbar spine and femoral neck than after treatment with chemotherapy only but the difference was not statistically significant. Because the bone mineral disturbances in the patients with multiple myeloma is the big problem there is a need for further and longer evaluation of the treatment of these disturbances.