Objective: To assess the effect of zoledronic acid (ZOL) on bone mineral density (BMD) and fracture risk at the L1-L4 vertebrae, femoral neck, hip and trochanter in Chinese women with osteoporosis. Methods: A randomized controlled trial was conducted in female patients with osteoporosis, randomized to receive one 5-mg ZOL intravenous infusion per year or placebo equivalent. Facture risk and BMD were measured over a 2-year follow-up period. Results: A statistically significant reduction in the risk of fracture was observed at the trochanter in the ZOL group (n ¼ 242) compared with the placebo group (n ¼ 241); (odds ratio 0.54 [95% confidence interval 0.29, 0.98]): BMD was 0.24, 0.28, 0.31 and 0.22 greater at the L1-L4 vertebrae, total hip, femoral neck and trochanter, respectively, in the ZOL group. The incidence of adverse events was comparable between treatment groups. Conclusions: This study indicated that ZOL could increase BMD and reduce fracture risk in women with osteoporosis over a 2-year follow-up period, and was not associated with any serious drug-related adverse effects.