2000 postmenopausal women with osteopenia were randomized to treatment with infusion of either zoledronate 5mg or placebo every 18 months for 6 years. Participants were assessed for incidence of fractures, prespecified adverse events including mortality, vascular events, cancer, and osteonecrosis of the jaw, and bone mineral density after 6 years. Results demonstrated significantly lower incidences of fragility fractures, including vertebral and nonvertebral fractures, among women administered zoledronate 5mg in comparison to placebo. No significant differences in the rates of adverse events were noted between groups, with the exception of a lower rate of cancer among the zoledronate group compared to placebo group. No participant in either group demonstrated atypical femoral fracture or osteonecrosis of the jaw. Bone mineral density measures at the lumbar spine, total hip, and total body demonstrated increases from baseline after 6 years in the zoledronate group, in contrast to decreases from baseline after 6 years in the placebo group.