Background: Osteoporosis is a growing health problem worldwide, and priority setting of researches and prevention efforts is a necessary issue.Methods: In our study, we calculated the Generalized Impact Fraction (GIF) index and avoidable burden of osteoporosis related to low calcium intake, smoking, reduced sun exposure, low physical activity, low body mass index (BMI) and systemic glucocorticoid therapy. These risk factors all can be intervened. Data about prevalence, casual effect and counterfactual prevalence of any of the above risk factors were obtained from different Iranian (and if needed non-Iranian) studies that contained best qualified evidence that was attainable.Findings: When counterfactual prevalence was considered 0% (theoretical minimum risk), GIFs of smoking, low calcium intake, reduced sun exposure, low physical activity, low BMI and systemic glucocorticoid therapy, were 0.038, 0.038, 0.110, 0.290, 0.211 and 0.020, respectively. When appropriate feasible minimum risk was considered as counterfactual prevalence, GIFs of smoking, low calcium intake, low physical activity, and systemic glucocorticoid therapy were 0.019, 0.010, 0.140 and 0.007, respectively.Conclusion: Interventions that reduce low physical activity should be given the highest priority in osteoporosis prevention strategies. However, the cost-effectiveness and practicality of any intervention must be appreciated.