The prevalence of osteoporosis increases with advancing age. Fractures are more common in women than in men and, apart from the menopause, the reasons for this difference remain poorly understood. The growth period is crucial to skeletal development and results in larger bones in males than in females. The sudden drop in estrogen levels that characterizes the menopause contrasts with the gradual decline in sex hormones seen in aging men, and the proportion of individuals with hypogonadism is considerably lower among older men than among older women. Although estrogens play a crucial role in bone homeostasis in both men and women, via direct and indirect mechanisms, differences exist between the sexes in hormonal physiopathology and its consequences on bone tissue. Many genetic and environmental factors influence the fracture risk. Although women are more prone to fractures, the mortality rate associated with fractures is higher in men. Most of the osteoporosis medications were developed for the treatment of postmenopausal osteoporosis and some are licensed for use only in women. Overall, the diagnosis of osteoporosis is somewhat less neglected than previously, but the treatment of high-risk individuals (those with a history of fracture) remains inadequate, most notably among males.