Male osteoporosis is increasingly recognized as an important public health issue. Possible factors include alcohol and tobacco consume and longer life expectancy. The main causes of male osteoporosis are secondary, as hypogonadism, use of glucorticoids and other drugs. The age-related decline in testosterone may be concomitant of ageing or may contribute to reduced bone formation and bone loss in men. Currently, therapy decisions are based on studies in women and animal models, once there is no trials with definitive results in men. Therefore, the aim of this review is to analyse some features of pathophysiology of bone loss in men, as well as the aetiological factors, clinical characteristics and therapy.