The incidence of osteoporotic fracture in males is approximately one-third of that observed in women, but information on specific therapies is almost exclusively limited to bisphosphonate alendronate. The most important study with this compound included 241 men, randomized to receive either alendronate 10 mg/day or placebo. In another study 134 men were given either 10 mg alendronate or alfacalcidiol 1 microg/day. After 24 months, the treatment with alendronate bone mineral density (BMD) significantly increased in both studies by 7-10% at the lumbar spine and by 2.5-5.2% at the femoral neck. These changes were associated with decreases in vertebral fracture rate and in stature loss, both statistically significant when the data of the two trials were meta-analysed. The BMD changes after alendronate therapy were comparable to those observed in postmenopausal osteoporosis. This was confirmed in a trial specifically designed to compare alendronate efficacy in men and postmenopausal women with either primary or secondary osteoporosis. Gender-comparative efficacy data can also be inferred from clinical trials in glucocorticoid-induced osteoporosis of alendronate, risedronate, and etidronate, carried out in both women and men. By combining the results of all these trials, bisphosphonate efficacy in terms of both BMD changes and fracture incidence appears to be moderate in premenopausal women but quite obvious and comparable in males and postmenopausal women.