Results of the European Working Party on High Blood Pressure in the Elderly (EWPHE) trial have been analysed in relation to age, sex, blood pressure, and previous cardiovascular disease. Cardiovascular mortality and the cardiovascular study-terminating events were significantly and independently related to treatment, age, cardiovascular complications at randomisation, and systolic but not diastolic blood pressure. The benefits of treatment observed in the trial seemed to be independent of entry blood pressure and the presence or absence of cardiovascular complications at entry. There was some evidence that treatment effect decreases with advancing age. Little or no benefit from treatment could be demonstrated in patients over the age of 80 years, the great majority of whom were women.