Abstract. In order to determine the role of polymorphic variants of the tumor necrosis factor α gene (TNFα -308G> A) in the development and course of chronic respiratory diseases, an analysis was made of the frequency of alleles and genotypes in patients with bronchial asthma and chronic bronchitis and healthy individuals of the Uzbek population. An analysis of the frequency distribution of genotypes and alleles of the studied gene showed that risk allele A and genotype A/A and A/G are markers of an increased risk of developing a disease of the bronchopulmonary system both in the group of patients with bronchial asthma and in children with chronic bronchitis.