In an open prospective study. 40 patients with progressing painful bone metastases received 45 mg pamidronate by 1-h infusion every 3 weeks. A total of 27 patients (67%; 95% CI 53%-81%) experienced relief of pain as shown by the significant reduction of the bone pain score after three pamidronate administrations (from 2.25 +/- 0.64 to 1.15 +/- 0.36). Furthermore, 20 patients (60%) reduced their consumption of analgesics. We did not observe any objective response by skeletal radiological examination. In 11 patients presenting a skeletal progressive disease, bone pain improved, as well as their mobility score, but not their fatigue score. Treatment was well tolerated. Only 1 patient discontinued the treatment because of fever and cutaneous rash after the first administration. In conclusion, our results seem to confirm that pamidronate exerts a benefical effect on bone pain and mobility impairment in patients with painful osteolytic bone metastases.