Abstract: An exopolysaccharide (EPS) in the amount of 20 mg/L and 1200 mg/L was obtained from the culture supernatant of Lactobacillus casei K7/3 grown in MRS broth and in a broth based on the whey of cottage cheese, respectivily. In the IR spectrum of EPS, intense absorption bands were found, generally characteristic of a class of carbohydrates. The molecular weight of the EPS obtained from L. casei K7/3 was 5600 Da, the polydispersity index was 1.9. The EPS from L. casei K7/3 consisted from a dextrose, mannose and galactose in molar ratio of 2.7:1.5:1, respectively. Minimal Inhibition Concentration (MIC) values of an EPS against Listeria monocytogenes ATCC 1911 revealed between 10 mg/mL and 80 mg/mL. An in vitro study of the antioxidant activity of L. casei K7/3 EPS in the diphenylpicrylhydrazine (DPPH) system showed that radical scavenging activity (RSA) has being increased depending on the concentration of the investigated EPS. The maximum %RSA was detected at 4 mg/ml being 26%.