Cereals grains are a rich source of biologically active compounds. They have antioxidant properties that depend on their chemical structure. This review paper depicted the physical and chemical composition of antioxidants, their chemical forms, and their contents in the grains of wheat, rye, oats, barley, and buckwheat. A general characteristic of the following groups of the antioxidants was represented: vitamins, carotenoids, phenolic compounds including phenolic acids and flavonoids, phytoestrogens, phytosterols, inositol phosphates, glutathione and melatonin, as was their role as antioxidants in preserving the homeostasis in human body. Discussed was the effect of milling grains and hydro-thermally processing them on the antioxidant potential of cereal-based products. The essential facts were provided on how new antioxidants were formed during the Maillard reaction after the hydrothermal treatment of cereal grains. Based on the constructive correlation as confirmed to exist between the consumption of whole grain products and the decreased occurrence level of non-communicable chronic diseases, as well as on the current dietary recommendations to increase the consumption of whole grain cereal products, the authors emphasis the necessity to pursue extended research into antioxidants in cereal grains and the health promoting value of whole grain cereal products pursue.