Asthma is a common chronic inflammatory condition with a highly complex genetic predisposition and environmental factors which play an important role in its development. Polymorphism in FOXO3a transcription factor has been linked to a number of inflammatory and respiratory diseases such as bronchiolitis and idiopathic pulmonary fibrosis suggesting that it may be implicated in the pathogenesis of asthma. This study aimed to investigate FOXO3a SNP (rs13217795) association with bronchial asthma and its degree of severity in adult Egyptian population. This case control study included 60 asthmatic patients and 40 apparently healthy controls. Peripheral blood samples were collected from all participants. Genotyping was performed using polymerase chain reaction-restriction fragment length polymorphism (PCR-RFLP). The study revealed high frequency of the mutant TT genotype of FOXO3a gene in asthma patients (51.7%) than controls (12.5%) with OR= 7.48 & 95% CI (2.58-21.71) (P˂0.05) and in severe cases (41.9%) compared to mild and moderate cases (25.8% and12.5%, respectively). T allele frequency showed significant statistical association with asthma, OR= 12.40, 95% CI (5.65-27.19) (P˂0.05). However, there was no association between T allele and disease severity. The high frequency of the mutant TT genotype among patients and sever cases may indicates that FOXO3a rs13217795 C>T single nucleotide polymorphism can be considered as a risk factor in development and severity of asthma.