Oleic acid has many beneficial effects on human health. One of the main dietary sources of oleic acid is olive oil. Non-Mediterranean European countries, including Serbia, have low habitual olive oil consumption, but other vegetable oils also contain different amounts of oleic acid. In infants and young children milk is the most important source of fatty acids, including oleic acid. Furthermore, fatty acid composition of plasma phospholipids reflects dietary intake and fatty acid metabolism. In patients with serious chronic diseases fatty acid status is altered independently on the intake. Here we reviewed status of oleic acid in healthy persons as well as in patients with different chronic diseases in Serbia.