An open-label study conducted in community centers assessed the safety of zoledronic acid 4 mg intravenously over 15 minutes every 3-4 weeks as treatment of bone metastases in patients with multiple myeloma, breast cancer, or prostate cancer with and without previous bisphosphonate exposure. Adverse events (AEs), pain, and quality-of-life (QOL) scores were recorded, and serum creatinine (SCr) levels were measured before each infusion. Of 638 patients, 415 patients (65%) had received prior bisphosphonate therapy. Fatigue, nausea, and arthralgia were the most frequent AEs. Nausea was more common in bisphosphonate-naive patients. SCr levels increased notably in 6.6% of patients: 7.7% of patients who received prior bisphosphonate therapy and 4.5% of bisphosphonate-naive patients. Treatment was delayed because of SCr-level increases in 1.4% of patients with prior bisphosphonate exposure and 0.4% of bisphosphonate-naive patients. SCr-level increases and treatment delays did not correlate with duration of prior bisphosphonate therapy. There was a trend towards more treatment discontinuations in patients with prior bisphosphonate exposure compared with bisphosphonate-naive patients. Pain scores decreased from baseline; total QOL scores remained constant. The results of this study suggest that, with proper SCr-level monitoring, cancer patients with bone metastases who have previously received intravenous bisphosphonate treatment can be safely converted to zoledronic acid therapy.