Olive oil is characterized by a pleasant and unique aroma, derived from the various constituents (vitamin E, phenol, aromatic substances ...). The largest part of oil take fatty acids, the most common of which is monounsaturated oleic acid, which is the reason why olive oil is the healthiest, and also the most stable (and ideal for cookery). Virgin olive oil is produced in the same way as extra virgin olive oil, but it has minor flaws in the flavour. The lowest quality among olive oils has refined olive oil, whose flavour and colour are enhanced by adding small amounts of (extra) virgin olive oil. Olive oil is the most important source of fat in Mediterranean diet, which is rich with vegetables and has moderate amount of animal origin food. Many guidelines for proper nutrition are similar to the Mediterranean diet and are a prerequisite for healthy lifestyle. The presence of vitamin E and other ingredients is the reason for recommending this oil as the main source of fat in daily diet. There have been legends about the healing properties of olive oil since the ancient history, and these were scientifically proved a decade ago. Unsaturated fatty acids, vitamin E, sterols and polyphenols reduce blood cholesterol, the risk of atherosclerosis and some types of cancer, preventing harmful processes in organism, such as fat oxidation. Unsaturated fatty acids from olive oil have the effect of lowering LDL cholesterol, the so-called bad cholesterol that can clog blood vessels, without affecting the amount of HDL, the so-called good cholesterol that cleans arteries. Its positive role is also indisputable in the diabetes diet, as well as in hypertension, prevention of gallstones, stomach and duodenal ulcer, obesity and constipation. It’s also proved that the risk of getting breast cancer is reduced for women, who consume olive oil on daily basis. Olive oil has for centuries been used by fishermen, as a protection from the sun, and the latest researches show its healing properties in case of sunburns.