Background: Bronchial asthma is a worldwide complex respiratory disorder manifested mainly by inflammations and reversible obstructions of the bronchial airways. Bronchial asthma results from multiple complex genetic and environmental interactions. Gene studies may help to control the development and progression of such a disorder which has tremendous health and economic burden. Objectives: to detect association among Interleukin-8-251 A/T (rs4073) polymorphism and the development of pediatric asthma .and its severity. Subjects and methods: This was a case-control study comprised of 80 cases (40 asthmatic and 40 controls). They were recruited from, Pediatric Department, Zagazig University Hospitals. Both groups were compared regarding pulmonary function, IL8 serum levels, and Interleukin-8-251 A/T (rs4073) polymorphism. The data were analyzed by SPSS version 26 with significance at p-value <0.05. Results: There is a highly significant level of serum IL-8 in asthmatic patients. There is a statistically significant association between asthma and Interleukin-8-251 A/T (rs4073) polymorphism. AT and TT genotypes increased the risk of asthma by 1.3 and 2.8 folds respectively, and the T allele by 1.81 folds. There is no association between asthma severity and Interleukin-8-251 A/T (rs4073) Polymorphism. Conclusion: Interleukin-8-251 A/T (rs4073) polymorphism has a significant function in pediatric asthma. It may predict the development of pediatric asthma but does not correlate with asthma severity. Keywords: asthma, pediatric, polymorphism