Among the most prominent health care issues of the 21st century are those relating to aging. Indeed, the elderly represent the fastest growing segment of our population. Typically, a urology practice includes a significant number of elderly males, providing the physician with both a challenge and an opportunity. Androgen deficiency in the aging male, with its detrimental effects on bone, muscle and body composition, sexual function, and psychological well-being, is an area of increasing interest in both the lay press and the medical community. The urologist must understand the pathophysiology of androgen deficiency in the male, recognize and investigate the subtle signs and symptoms of hypogonadism, determine the appropriateness of treatment, and offer informed options to the patient. Health care professionals have a responsibility to make "healthy" aging a priority.