Bisphosphonates represent nowadays a standard therapy of tumor induced hypercalcemia and are progressively more used in the treatment of tumor bone metastatic disease. Among several bisphosphonates, pamidronate is one of the most commonly used in clinical practice, so we also used it in succesful treatment of patients with breast cancer bone metastases. It has been shown that pamidronate reduces the frequency of hypercalcemia, bone pain and pathological fractures, although the mechanisms by which these effects are achieved are not completely clarified. Bisphosphonates are also important not only in treating patients with present metastases but also in prevention, or at least, delay of bone metastases onset. Recently, there are clinical trials examining the so called adjuvant therapy, that means the use of bisphosphonates in prevention of bone metastases in high risk breast cancer patients without distant metastases. In addition to breast cancer, multiple myeloma is another area of successful bisphosphonate application. In this paper we present some of the clinical results following the use of pamidronate in breast cancer- and hypernephroma-patients with hypercalcemia.