The purpose of this paper is to assess the efficacy and safety of the Bisphosphonate treatment. 20 patients with skeletal metastases were studied: 14 breast cancer, 5 prostate cancer, 1 uterine cervix cancer. The medium time of the observation was 21.4 months. The medium number of cycles was 12.5. The medium time to the first skeletal related event was 9.9 months shorter by the prostate cancer patients versus the breast cancer patients. Renal failure has been observed in 1 patient with cancer of the uterine cervix. Conclusions : the bisphosphonates reduce the skeletal complications of malignancies.