The results of investigation the features of genotype СУР 2С9 in patients with NSAIDs-induced gastrointestinal bleeding are presented in the article. In conclusion, genotypes CYP 2C9*1/*3 and CYP 2C9*1/*2 are associated with high risk of gastrointestinal bleeding, whereas the presence of the genotype CYP 2C9*2/*3 is not significantly associated with this risk. CYP 2C9 genotyping may be useful in identifying the subgroup of patients with potentially higher risk of gastroduodenal bleeding when treated with NSAIDs metabolized by CYP 2C9. Further studies involving more patients to evaluate the effectiveness of CYP 2C9 genotyping in NSAID users are needed before this method will be introduced into clinical practice.