Although estrogen replacement therapy has become well established in the management of postmenopausal women, most physicians pay much less attention to the testosterone status of their older male patients. There is now increasing evidence that testosterone deficiency-Low Testosterone Syndrome-occurs in older men and is associated with decreased muscle strength and bone density, as well as memory problems. This article reviews the evidence for the existence of Low Testosterone Syndrome, often characterized as the male menopause or viropause, and the emerging evidence that testosterone therapy may ameliorate some of the symptoms and signs of frailty in men beyond 50 years of age.