Antiviral drug Kagocel in concentrations of 0.0008, 0.004, 0.02, 0.1, 0.5, and 2.5 mg/ml with or without metabolic activation does not induce gene mutations in S. typhimurium strains ТА98, ТА100, ТА1535, and ТА1537 and in a combination of E. coli strains pKM101 and uvrA. A single intragastric administration of Kagocel in a daily therapeutic dose and a 10-fold daily therapeutic dose to male mice or multiple administrations in daily therapeutic dose to male and female mice did not led to a significant increase in the percentage of chromosomal aberrations in the bone marrow cells. DNA comet assay revealed no significant increase in the incidence of DNA breaks in cells of mouse testes after single or multiple administration of Kagocel at daily therapeutic and 10-fold daily therapeutic doses. Our results indicate that Kagocel exhibits no genotoxic activity in the studied dose range.