OBJECTIVE: Post-menopausal osteoporosis has significant health care costs and impacts quality of life. The objective of this analysis was to assess the cost-effectiveness of risedronate compared to calcium + vitamin D, etidronate, alendronate, and ibandronate in high-risk osteoporotic patients in Germany. METHODS: A validated model (Tosteson, 2001) was used to estimate the impact of therapy on hip and vertebral fractures, costs, and quality adjusted life years (QALYs). The analysis included women 70 years with a BMD T-Score of RESULTS: In a cohort of 1000 postmenopausal women with 3 years of treatment the model predicted the following costs, total hip and hospitalized vertebral fractures and QALYs: risedronate (€8.22M, 139, 5451); alendronate (€8.41M, 142, 5447); etidronate (€8.42M, 149, 5441); ibandronate (€9.33M, 159, 5429); calcium + vitamin D (€7.91M, 164, 5427). All bisphosphonates were dominated by risedronate, which was less costly and had better outcomes. Risedronate had a cost per fracture averted of €12,389 and a cost per QALY gained of €13,253, compared to calcium + vitamin D. CONCLUSIONS : The analysis favors the adoption of risedronate therapy for the treatment of postmenopausal osteoporosis compared to other bisphosphonates.