AbstractThis is the first study to analyze the variability of two exons (the 1st and 3rd) of the VCORC1 gene in Russian populations of mice and rats, namely, 125 Mus musculus and 19 Rattus norvegicus captured in 13 settlements. Previously, it has been shown that a number of mutations in these exons in the countries of Western Europe are associated with resistance to anticoagulants in synanthropic rodents. We did not find such mutations in house mice in Russia. However, in the first exon, two previously unknown mutations were identified that could potentially have such an effect (Lys58Arg and Ser31Trp). In three districts of Moscow, Norway rats were found carrying in the third exon a previously known resistance mutation (Tyr139Ser) in the heterozygous state. The results are discussed in connection with the intensity of the use of anticoagulants in the settlements of Russia and the mutation rate of the VCORC1 gene.