Phytonutrients, or phytochemicals, are compounds from plants that have a beneficial effect on the human body. Phytochemicals serve plants with various important functions, such as defense against pathogens, UV radiation, pollination, protection from herbivores, and for humans, although they are not essential, they are very useful for improving health and often serve the purpose of preventive action. They are most often divided into several large groups such as alkaloids, organosulfur compounds, carotenoids, phytosterols and polyphenols, which are further divided into smaller subgroups. These groups include well-known compounds such as caffeine, thein, ß-carotene, lycopene, quercetin, resveratrol, anthocyanides and many others. One of the most commonly mentioned properties of phytonutrients is antioxidant activity, but they can also be prescribed anticancer, anti-inflammatory, immunostimulating and many other properties. The Mediterranean diet, which is characteristic of our climate, is rich in phytonutrients and as such is recommended in other parts of the world. Many other foods also contain these substances and it is recommended to introduce them into your daily diet.