The European Working Party on High Blood Pressure in the Elderly (EWPHE) trial was a double-blind randomized placebo-controlled trial of antihypertensive treatment in patients over the age of 60 years. Entry criteria included both a sitting diastolic blood pressure on placebo treatment in the range 90-119 mmHg and a systolic blood pressure in the range of 160-239 mmHg. The patients (n = 840) were randomized either to active treatment (hydrochlorothiazide + triamterene) or matching placebo. If the blood pressure remained elevated, methyldopa was added to the active regimen and matching placebo in the placebo group. An overall intention-to-treat analysis, combining the double-blind part of the trial and all subsequent follow-up, revealed a non-significant change in total mortality rate (-9%, P = 0.41) but a significant reduction of cardiovascular mortality rate (-27%, P = 0.037). The latter was due to a reduction of cardiac mortality (-38%, P = 0.036) and to a non-significant decrease of cerebrovascular mortality (-32%, P = 0.16). In the double-blind part of the trial, total mortality rate was not significantly reduced (-26%, P = 0.077). Cardiovascular mortality was reduced in the actively treated group (-38%, P = 0.023), due to a reduction of cardiac deaths (-47%, P = 0.048) and to a non-significant decrease of cerebrovascular mortality (-43%, P = 0.15). Deaths from myocardial infarction were reduced (-60%, P = 0.043). Study-terminating morbid cardiovascular events were significantly reduced by active treatment (-60%, P = 0.0064). In the patients randomized to active treatment there were 14 fewer cardiovascular deaths per 1000 patient-years during the double-blind part of the trial. Version 3.