Hypertension is a major independent risk factor for cardiovascular events and death. Moreover, it generally occurs in conjunction with other cardiovascular risk factors (e.g. dyslipidaemia, diabetes, obesity, left ventricular hypertrophy) which greatly increase the overall risk of adverse cardiovascular outcomes.Diet and lifestyle modifications are recommended for all patients with hypertension; however, most will also require pharmacological therapy. To date, only diuretic- and &bgr;-blocker-based regimens have been shown to reduce cardiovascular morbidity and mortality in long term outcome studies; therefore, these agents are the preferred first-line drugs in patients with hypertension according to most expert committee guidelines. Newer agents (i.e. ACE inhibitors, calcium antagonists, &agr;1-blockers) show antihypertensive efficacy equivalent to diuretics and &bgr;-blockers, but long term outcome data are not yet available for the newer drugs. The newer drugs also appear to have important roles in the treatment of hypertensive patients with concomitant disorders (e.g. ACE inhibitors in patients with congestive heart failure).Losartan (losartan potassium) is the first angiotensin II antagonist available for clinical use. It has been shown to be as effective as the well established agents atenolol, enalapril, amlodipine and long-acting formulations of felodipine and nifedipine in reducing blood pressure in patients with hypertension. It has additive effects when used in combination with hydrochlorothiazide. Losartan has been well tolerated in clinical trials to date and, in contrast with ACE inhibitors, does not cause cough. However, the results of ongoing long term studies, as well as studies in special patient populations, are needed to clarify the role of losartan in the management of hypertension. Pending these results, losartan should have the same positioning as ACE inhibitors, calcium antagonists and &agr;1-blockers in most management protocols for hypertension, i.e., as an alternative first-line agent to diuretics and &bgr;-blockers and for patients who are not adequately managed with, or who are intolerant of, their current therapy. It is likely that losartan will find a particular niche in patients unable to tolerate ACE inhibitors because of persistent cough.