Osteoporosis is known to increase in prevalence with age. With aging of population in the recent years, the number of male osteoporosis patients is increasing. Osteoporosis can progress without symptoms. Diagnosis and treatment of osteoporosis are often delayed especially in men, because the concept of male osteoporosis has not been fully penetrated. Even after fragile fracture caused by osteoporosis, it is frequent that an appropriate treatment for osteoporosis has not been provided in men. Furthermore, it has been reported that about half of male osteoporosis patients have secondary causes. In management of osteoporosis patients, we have to pay attention to background diseases and life style of the patients.