The aim of the study was to determine the effect of the addition of antioxidants on changes in contents of available lysine and methionine in raw Polish sausage. Experimental material consisted of four variants of experimental sausages. One variant consisted of a sample with no antioxidant added (control), while the following were added to the other variants: BHT (0.02%), rosemary ethanol extract (0.05%) and soy protein hydrolysate (2%). Oxidation degree of lipid using peroxide value (PV), anisidine value (AV), thiobarbituric acid reactive substances (TBARS) and the Totox index was controlled and content of available lysine and methionine were determined periodically. In order to determine the effect of the addition of antioxidants on the stability of available lysine and methionine, values of the coefficient of the slope of curve of changes in time (coefficient a/24 h) were analyzed along with the half-life period of the amino acids (T_IC50). Antioxidants exhibited an inhibitory effect on the advancement of lipid autoxidation reactions and reduced quantitative losses of available lysine and methionine in analyzed sausages. Natural antioxidants exhibited a lower capacity to reduce losses of nutritive value of protein than it was found for BHT.