The objective of the research study was to evaluate the oxidative stability of dry-fermented sausage with acid whey or probiotic strain (Lb. casei ŁOCK 0900) added during a four-month period of chilling storage (4° C). Four experimental varieties of the product were manufactured: K pickled sausage as a control sample (2.8 % of pickling salts); L sausage with sea salt (2.8 %) and Lb. casei ŁOCK 0900 (log 6.3 cfu/g) probiotic strain; S sausage with the sea salt (2.8 %) and acid whey (5.0 %); LG sausage with the sea salt (2.8 %), probiotic strain, and glucose (0.6 %). The research covered the determination of the pH value, water activity (a_w), oxidation-reduction potential (ORP), peroxide value (PV), TBARS value, reflectancy spectrum as well as the oxidation value and 650/570 nm index to characterize the colour parameters of the product after ripening process (0) and after the four-month period of chilling storage. The count of lactic acid bacteria (LAB) was also determined after the four-month storage period. Compared to other samples, a significantly lower (p < 0.001) pH value was reported in the sample with the probiotic bacteria and glucose (LC) added, and in the sample with the acid whey (S) added immediately after dry-fermenting and during storage period. Compared to other samples, significantly lower peroxide values were reported in the control sample (K) and in the sample with probiotic (L) after dryfermenting process. Except for the sample with probiotic and glucose (LG), in all the products the peroxide value increased significantly by ca. 2.0 meqO₂/kg after the four-month storage period. Compared to other samples, significantly higher TBARS values were determined in the samples with the acid whey (S) added as well as in the samples with probiotic and glucose (LC) added. The oxidation processes were the slowest in the pickled control sample (K). In the sample with the strain of Lb. casei ŁOCK 0900 added, the variant with the glucose (LC) added was characterized by the lowest oxidation value and 650/570 nm index; this fact proved that the colour developed in the product was similar to the colour of the pickled product. The highest 650/570 nm index was obtained in the sample with the addition of acid whey (S) after dry-fermenting and after the four-month storage period. The oxidation stability of the samples evaluated decreased as follows: K > LG > L > S. In all the studied samples, the number of lactic acid bacteria was reported to be higher than log 7.0 cfu/g.