Bronchial asthma (BA) is a serious global health problem affecting all age groups. Its prevalence is increasing in many countries, especially among children. Vitamin D deficiency and single nucleotide polymorphisms (SNP) in the gene encoding vitamin D receptor (VDR) have been associated with asthma.The aim was to assess the role of serum 25OHD level and VDR SNP fok1 rs 10735810 as predictors of therapy response in asthmatic children. Patient : 96 subjects were enrolled in the study; classified into (32 children with controlled bronchial asthma, 32 children with uncontrolled bronchial asthma and 32 healthy children). All participants were subjected to serum 25OHD level measurement and Polymerase chain reaction-restriction fragment length polymorphism (PCR-RFLP) for VDR gene FokI polymorphism . Results: There was highly statistical significant difference (P< 0.001) between the three studied groups regarding vitamin D levels. While, there was no statistically significant association (P≥0.05) between vitamin D levels and GINA. Regarding VDR FOK1, there was statistically significant difference (P< 0.001) between the asthmatic and healthy control groups regarding the frequency of both Ff and FF genotypes with a p value of (0.027 & 0.002 respectively). there was statistically significant association (P