The genotoxic properties of three new azoloazine derivatives (azoloazines 1 – 3) exhibiting cytotoxic activity were studied in an in vitro experiment using MCF-7 human breast cancer cell culture. Acomparison of the effects of azoloazines 1 – 3 at doses of 1/2, 1/10, and 1/50 of IC50 with those of epirubicin at the same doses on the main indicators of damage to the genetic apparatus of the cells revealed that the studied compounds had the greatest toxic effect on DNAat a dose 1/10 of IC50. The genotoxicity of azoloazines 1 – 3 at a dose 1/10 of IC50 was shown to exceed that of epirubicin. © 2023, Springer Science+Business Media, LLC, part of Springer Nature.