The treatment of BPH by alpha blockade is built upon a sound anatomical, physiological and pharmacological rationale. The theory is borne out in clinical practice; alpha adrenoceptor antagonists have been shown in placebo-controlled studies to improve symptoms of BPH and increase urinary flow rate. In hypertensive patients, there is a clinically significant reduction in blood pressure, with little or no effect on the blood pressure of normotensive patients with BPH. The development of selective alpha-1 adrenoceptor antagonists with a gradual onset and long duration of action has improved the tolerability and makes this class of drug a valuable alternative to surgery in many cases. Further refinements in the selectivity of alpha-1 adrenoceptor antagonists may enable even better targeted alpha blockade for BPH in the future by specific antagonism of the alpha-1 A adrenoceptor, although this hypothesis has yet to be confirmed clinically.