The results of several important clinical trials have confirmed the benefits of pharmacologic treatment in patients with hypertension. However, some issues concerning this type of treatment have yet to be resolved. For example, it has not been determined whether there are differences among antihypertensive agents with respect to their effects on mortality and morbidity or whether such effects are independent of the alterations in blood pressure resulting from the use of such agents. Thiazide diuretics, the most commonly prescribed antihypertensive drugs, were the first agents proven to be effective and practical for the widespread treatment of hypertension. Alpha blockers, also commonly prescribed antihypertensive drugs, provide equally effective blood pressure control to that of the thiazides, but with a very different metabolic profile. In this article, these drugs are compared for efficacy, side-effect profiles, metabolic effects, and potential for reducing the risk of coronary heart disease.