Osteoporosis in men is a prevalent, worldwide, clinical problem that has been relatively under-recognized. This article reviews the scope of the problem in men and the key differences in the pathogenesis of this condition between men and women. The current understanding on the role of estrogens and androgens for the bone health of men is discussed. The review concludes with an overview of other risk factors for low bone density and osteoporotic fracture in men and also general recommendations for the management of male osteoporosis.