Blood pressure levels increase with age. So, the prevalence of both isolated systolic (systolic pressure greater than 160 mmHg and diastolic less than 90 mmHg) and diastolic hypertension (diastolic pressure greater than 95 mmHg) in the elderly is high. Due to high variability of blood pressure and to overestimation of real blood pressure when arterial walls are sclerosed, the true prevalence of hypertension is probably overestimated. Nevertheless, like in younger persons, hypertension in elderly is a major risk factor of cardiovascular morbidity and mortality. Results of clinical trials designed in the last 30 years have clearly proved benefit of antihypertensive therapy. However, a lot of questions remain: Is treating hypertension justified in the very old? Has isolated systolic hypertension to be treated? Which antihypertensive drugs may be used? Is screening for atherosclerotic renovascular disease useful? Which investigations have to be performed for diagnosing atheromatous renal failure?