The lifetime risk of fracture in white women is 20% for the spine, 15% for the wrist, and 18% for the hip, with an exponential increase in risk beyond the age of 50 years.We conducted a systematic review and aimed to answer the following clinical question: What are the effects of treatments to prevent fractures in postmenopausal women? We searched: Medline, Embase, The Cochrane Library and other important databases up to January 2007. (BMJ Clinical evidence reviews are updated periodically, please check our website for the most up-to-date version of this review). We included harms alerts from relevant organisations such as the US Food and Drug Administration (FDA) and the UK Medicines and Healthcare products Regulatory Agency (MHRA).We found 61 systematic reviews, RCTs, or observational studies that met our inclusion criteria. We performed a GRADE evaluation of the quality of evidence for interventions.In this systematic review we present information relating to the effectiveness and safety of the following interventions: alendronate, calcitonin, calcium, calcium plus vitamin D, clodronate, etidronate, exercise, hip protectors, hormone replacement therapy, ibandronate, multifactorial non-pharmacological interventions, pamidronate, parathyroid hormone, raloxifene, risedronate, strontium ranelate, vitamin D, and vitamin D analogues.