Introduction. The frequency of functionally relevant alleles and polymorphisms of genes encoding xenobiotic metabolizing enzymes has wide ethnic variation. Pharmacogenetic studies of the frequency of genotypes and allelic variants *2 (С430Т) and *3 (А1075С) of CYP2C9 gene were not conducted in Ukraine.
Materials and methods. Polymerase chain reaction and restriction fragment length polymorphism were used to determine the genotypes of CYP2C9 in 918 healthy men and women of Ukrainian origin.
Results and discussion. On the basis of the molecular-genetic examination it was defined the distribution of allelic variants *2 (С430T) and *3 (A1075С) of CYP2C9 gene in the population of Ukraine. There were no significant difference in the distribution of alleles *2 and *3 of CYP2C9 gene among the Ukrainians of varying gender and different age groups. There was detect a statistically significant difference for genotype *2*2 (T430T) of CYP2C9 gene in the comparison of the theoretically expected genotype frequencies with the receipt. It was conducted a comparative assessment of the CYP2C9 allele frequency in Ukrainian people and the other ethnic groups.
Conclusion. Assessment of the distribution of CYP2C9 alleles, important xenobiotic metabolizing enzymes among the Ukrainian population shows similarities to other Caucasians. Examination of the frequencies of this gene, suggest the feasibility of their research before prescribing pharmacotherapy.