The risk of hypertension and the benefits of antihypertensive treatment are well established in older patients aged up to 80 years. For people aged 85 and over, data are scarce and conflicting. A positive association between blood pressure and survival has been found in several cohort studies; this relationship held true after adjustment for many factors in some studies, but disappeared after adjustment for indicators of poor health in others. In randomized trials, the benefit of antihypertensive treatment was demonstrated in the Systolic Hypertension in the Elderly Program (SHEP) study, but it declined with age and was not observable after 80 years in the European Working Party on High Blood Pressure in the Elderly (EWPHE) study. The SYSTolic hypertension in elderly in EURope Trial (SYST-EUR) study evidenced a benefit on cardiovascular morbidity but not on mortality. People who reach a very old age share some characteristics that make them different from those '60 (or 65) and over' and justify special studies which are currently in progress. In the meantime, any treatment decision can only rely on extrapolations moderated by common sense, but the already demonstrated favorable results on morbidity argue against a threshold beyond which hypertension should not be treated.