Olive oil is known as a valuable vegetable oil and, as such, used throughout the world. Scientific research results confirm the beneficial effect of olive oil and Mediterranean diet on health, especially on the health of people living in areas situated along the Mediterranean Sea. Based on the literature review, it was found that the most valuable olive oil, the extra virgin oil, contains many beneficial nutrients, such as: oleic acid, the one of fatty acids, as well as phenolic compounds, b-sitosterol, a-tocopherol, and squalene that protect people against lifestyle diseases. The highest production and consumption of olive oil is in the Mediterranean Basin countries. The Mediterranean diet is characterized by a balanced composition of food products and includes, in the first instance, cereal products, and, next, fruits, vegetables, and legumes. Olive oil is the main source of fat in this diet. Only a complete diet combined with physical activity and with drinking plenty of water is able to keep the human body in a proper state of health.