 Hypertension affects about 30 of the United Kingdom population and is causally implicated in the aetiology of renal disease, cardiovascular disease and stroke. Ageing, obesity, a poor diet and low levels of physical activity are all risk factors. Studies have shown that adherence to a Mediterranean diet is protective against hypertension and its associated morbidities; olive oil is believed to be a key beneficially bioactive component of that diet. As a source of lipids olive oil is an unremarkable blend of monounsaturated, polyunsaturated and saturated fatty acids; it is however rich in phenolic compounds, principally oleuropein and hydroxytyrosol, which may be of benefit to health. A recent randomised intervention trial in predominantly hypertensive volunteers showed that adherence to a Mediterranean diet supplemented with extra virgin olive oil, reduced blood pressure and other measures of cardiovascular disease risk. Olive phenolics can be extracted cheaply from the waste products of olive oil manufacture, such as the plant leaf and these are used as dietary supplements. In intervention studies in hypertensive or borderline hypertensive patients, olive leaf extract consumption has been shown to reduce blood pressure. 