Hypertension is a major risk factor for stroke and coronary heart disease and this increases with increasing age. It is a chronic disease which affects a quarter of the adult population. On its own or in conjunction with other risk factors, especially cigarette smoking, hypertension is associated with serious morbidity and high mortality. A large number of clinical trials have been undertaken to assess the efficacy of antihypertensive therapy in controlling high blood pressure and in reducing the morbidity and mortality associated with hypertension. These trials have studied more than 40,000 subjects worldwide as a result of which the benefits of treatment even in milder forms of hypertension are well established today. However, antihypertensive therapy has been disappointingly unsuccessful in the primary prevention of coronary artery disease despite the undoubted protection against malignant phase hypertension, heart failure, stroke and renal failure as demonstrated in the early Veterans Administration trial and subsequent studies. The success of post-infarction beta-blockade suggested that the wider use of beta-blockers prophylactically might limit hypertension-related coronary disease. Taking into account the adverse and metabolic effects of thiazide diuretics, beta-blockers together with calcium channel blockers must remain the drugs of choice as step one therapy in most patients with hypertension.