Oatmeal and oat products are an important source of fat, dietary fibre, carbohydrates, mineral compounds, vitamins, and, first of all, proteins. Enzymatic hydrolysis of proteins leads to the release of peptides, which may show various activities including antioxidant activity. The objective of the research study performed was to determine the antioxidant properties of oat protein hydrolysates obtained from the 12 varieties (genotypes) of cultivated and wild hexa-and tetraploid species of the Avena L genus. The protein isolate (IBO₉) obtained from grains of the A. maroccana CN 43136 wild oats was characterised by the highest number of polymorphic protein fractions. Furthermore, the HBO₉ hydrolysate obtained from proteins contained in the grains of the A. maroccana CN 43136 oats showed the highest ability to neutralize free radicals generated from ABTS and DPPH: 87.27 % and 46 %, respectively. On the other hand, the highest ability to chelate iron (II) – 90.12 % was determined for wild HBO₇ (A. sterilis AVE 2116). It was confirmed that the inter-specific crosses increased the antioxidant properties of oat protein hydrolysates and, thus, beneficially impacted the pro-health properties of grains.