Androgen deficiency in the aging male (ADAM), also known as andropause, affects an estimated 1 in 200 men. The abnormally low levels of testosterone in these men can usually be managed with androgen supplementation therapy. Because a large proportion of urologic patients are men at or beyond middle age, urologists should be familiar with ADAM, its clinical manifestations, the rational approach to its diagnosis and treatment, and the consequences of treatment. Equally important is responsibility for the patient's monitoring, because prolonged androgen replacement therapy can be associated with significant complications, particularly in the prostrate.