Osteoporosis is a systemic metabolic disorder associated with a decreased bone mass and resistance. Bisphosphonates suppress bone resorption and bone turnover by a mechanism that depends on their structure. They are characterized by low gastrointestinal absorption. In postmenopausal women, alendronate (ALN) reduces bone resorption markers and increases bone mineral density (BMD) in the lumbar spine, femoral neck, and total body. Individuals receiving ALN have been studied for up to 10 years with an apparent linear increase in BMD over that time period estimated at 13.7% at the lumbar spine. Treatment with ALN reduced the risk of both vertebral and non-vertebral fractures, including hip fractures, in postmenopausal women with osteoporosis. Direct comparisons of the results obtained with different antiresortive agents is difficult, because the designs of the respective studies, populations and other factors. However, the meta-analysis of available publications seems to indicate that ALN reduces the relative risk of vertebral fractures in a greater proportion than any other agent. Furthermore, ALN prevents the reduction in BMD after hormone replacement therapy discontinuation.