Oat grain gross chemical composition, and amino acid composition of oat grain protein was presented. Studies on human amino acid requirements and resulting modifications of recommended (FAO/WHO) amino acid scoring patterns, in the years of 1970-1990, were also discussed. In addition, the current protein digestibility-corrected amino acid scoring method, recommended by FAOAVHO (1991), for routine evaluation of protein quality quality for humans, was described. The available literature data on protein quality of oat grain protein (for covered and naked cultivars), both Canadian and Polish, were presented. Generally, protein quality of covered culivars was higher than that of naked ones. As indicated by the data, lysine was the first limiting amino acid for covered and naked oat cultivars.