Postmenopausal osteoporosis is characterized by an increased rate of bone turnover accompanied by a reduction in bone mineral density (BMD) that results in an increased risk of fracture, especially of the vertebrae, hip, or wrist. Alendronate (Fosamax®, Fosamax Once-Weekly®), an oral bisphosphonate that inhibits osteoclast-mediated bone resorption and modulates bone metabolism, is a first-line therapy for the management of postmenopausal women with, or at risk of developing, osteoporosis.Alendronate produces sustained increases in BMD and reductions in bone turnover from baseline, and reduces the risk of vertebral, hip, wrist, and other fractures in women with postmenopausal osteoporosis. It also prevents bone loss, and reduces the risk of radiographic or clinical vertebral fracture in postmenopausal osteopenia. Provided administration instructions are followed, alendronate is generally well tolerated. Adverse events are usually transient and are associated with the upper gastrointestinal tract (abdominal pain, nausea, acid regurgitation, dyspepsia); moreover, the incidence of these adverse events with alendronate was similar to those with placebo. More serious events (esophagitis, gastric or duodenal ulceration or bleeding) are uncommon. Once-weekly formulations are as effective and as well tolerated as once-daily alendronate in postmenopausal women.Pharmacoeconomic evaluations suggest that alendronate is a viable treatment option in postmenopausal osteoporosis. The reduction in fracture-related healthcare utilization seen with alendronate results in decreased direct costs, including inpatient or long-term care. Markov state-transition models suggest that this could at least partially offset costs incurred with alendronate therapy. Treatment of women with osteoporosis aged 65 years and older, and postmenopausal women with a previous osteoporotic fracture, are cost-effective strategies. Alendronate is also likely to increase quality-adjusted life-years in any postmenopausal women with osteoporosis.In conclusion, clinical and economic data support the use of alendronate in postmenopausal osteoporosis. It effectively reduces bone turnover, increases BMD, and reduces the risk of osteoporotic fracture in postmenopausal women with established osteoporosis, especially older women with a higher risk of fracture. Although its cost effectiveness in postmenopausal women with osteopenia is not clearly established, alendronate is clinically effective in these patients. In addition, it is generally well tolerated when taken as recommended. Consequently, alendronate should be considered a therapy of choice in the prevention and treatment of osteoporosis in postmenopausal women.