The treatment of hypercalcemia of malignancy is troublesome. Personal experience with breast cancer associated hypercalcemia is presented. Eight patients were hydrated with intravenous administration of saline solution containing high doses of salmon calcitonin and subsequently six were treated with antiblastic polychemotherapy. Calcium level fell to normal in all patients. Hypercalcemia, with or without evidence of metastatic bone disease, may be caused by the production of humoral substance by tumoral tissue. In our experience the first therapeutic stage is the infusion of saline solution containing high doses of calcitonin, while the elective treatment is antiblastic polychemotherapy which, acting on tumour growth, may inhibit the release of humoral mediators of hypercalcemia causing a slower but stable reduction in serum calcium level.