Background: Asthma is a global health problem affecting millions of adults and children. Pathogenesis of asthma is multifactorial and the genetic component is of particular importance. Objectives: To assess the role of ADRB2 Thr164Ile gene polymorphism in asthma risk, severity and response to β2 agonist therapy in Egyptian children. Methodology: The study enrolled 50 asthmatic and 50 control children. Pulmonary function tests and serum levels of IgE of asthmatic children were measured. The Thr164Ile genotypes were detected for all study subjects by Amplification Refractory Mutation System- Polymerase Chain Reaction (ARMS-PCR). Results: Serum IgE levels were significantly higher on comparing mild to moderate and severe cases (P=0.002& 0.02, respectively). The Ile/Ile genotype of Thr164Ile SNP was significantly present in asthmatic subjects (P=0.039). The Thr164Ile SNP was associated with lowered response to β2 agonist inhalation (P<0.001) but there was no association between the studied SNP and asthma severity. Conclusion: The Thr164Ile SNP can be linked to asthma risk and lowered response to β2 agonist treatment but not to asthma severity in asthmatic children.