Herpes viral infection is the most common human viral infection. It is known that lactic acid bacteria (LAB) can be used as a source of the substances with the diverse chemical structures and spectrum of biological activity for designing of products for medical purposes. Thus the screening of compounds with antiviral activity among such bacteria is still valid and has practical significance for the development of new antiherpetic drugs. The aim of this work was to study the antiviral properties of 10 exopolysaccharides (EPSs) of lactic acid bacteria of the genera Lactobacillus, Leuconostoc and Pediococcus. Cytotoxicity and antiviral activity of EPSs were determined in cell culture MDBK by standard technique using MTT assay. The influence of EPSs on the herpes simplex virus 1 type (HSV-1) was determined by the virucidal, adsorption and penetration assays. All EPSs demonstrated the minimal cytotoxicity of cells and their CC50 values were >2.7 mg/ml. It was determined, that EPSs exhibited in vitro anti-HSV-1 activities at different magnitudes of potency; their EC50 value equal to 0.2 and 1.1 mg/ml, and the selectivity index was in the range of 3 – 52. To determine the stage of the HSV-1 inhibited infection, the virus and cells were treated with the compounds at various times before and after the HSV-1 infections. The exopolysaccharides showed virucidal activity and reduced the HSV-1 infectivity by 64 – 98% when were added to virus 3 h before adsorption. Our studies revealed that EPSs were able to prevent the HSV-1 attachment to cells and penetration into cells by 53 – 99% and 51 – 99 %, respectively. When the compounds were added to cells at the end of the virus adsorption period (2 h after infection), a significant delay in the growth of HSV-1 was observed, and a much lower yield of infectious virus was also obtained. The EPS 6, EPS 8, EPS 9 and EPS 10 reduced HSV-1 virus production by 30 – 58%, 62 – 80%, 34 – 58% and 50 – 99%, respectively. Thus, we showed that isolated exopolysaccharides (EPS) of lactic acid bacteria of the genera Lactobacillus and Leuconostoc possess the antiviral activity and cause inhibition of HSV-1 reproduction. The data indicate that the use of EPSs of lactic acid bacteria in creation of the new classes of drugs is a promising approach for the treatment of diseases caused by herpes simplex virus.