Detection, treatment and control of hypertension is one of the best proven approaches to prevention of cardiovascular disease. Antihypertensive treatment trials have convincingly demonstrated that diuretics and beta-blockers reduce the risk of stroke and coronary heart disease. Corresponding information is not yet available for newer classes of antihypertensive drug therapy such as calcium channel blockers, angiotensin converting enzyme inhibitors and alpha 1 receptor blockers. Several experimental studies are now addressing this question. The largest such trial (n = 40,000) is the Antihypertensive and Lipid-Lowering Treatment to Prevent Heart Attack Trial (ALLHAT). This manuscript describes two studies (TOMHS and the VA study on antihypertensive agents) that compared several classes of antihypertensive drugs with regard to blood pressure outcomes and ALLHAT, which is comparing the effect of four first-step approaches to antihypertensive therapy on combined incidence of fatal coronary heart disease and non-fatal myocardial infarction.