Context A negative association between a history of allergy and childhood acute lymphoblastic leukaemia (ALL) has been reported in previous studies, but remains debated. This work aimed to investigate this association accounting for genetic polymorphisms of the Th2 pathway cytokines (IL4, IL10, IL13 and IL4-receptor (IL4R)). Methods Analyses were based on the French case-control study ESTELLE (2010-2011). The complete sample included 629 ALL cases and 1,421 population-based controls frequency-matched on age and gender. The child's medical history was collected through standardised maternal interview. Biological samples were collected, and genotyping data were available for 411 cases and 704 controls of European origin. Odds ratios (OR) were estimated using unconditional regression models adjusted for potential confounders. Results In the complete sample, a significant inverse association was observed between ALL and reported history of allergic rhinitis or sinusitis (OR=0.65 [0.42-0.98]; p= 0.04), but there was no obvious association with allergies overall. There was an interaction between genetic polymorphisms in IL4 and IL4R (pinteraction=0.003), as well as a gene-environment interaction between IL4R-rs1801275 and a reported history of asthma (IOR=0.23; pint=0.008) and eczema (IOR= 0.47; pint=0.06). We observed no interaction with the candidate polymorphisms in IL4 and IL13. Conclusion These results suggest that the association between allergic symptoms and childhood ALL could be modified by IL4R-rs1801275, and that this variant could also interact with a functional variant in IL4 gene. While they warrant confirmation, these results could help understand the pathological mechanisms under the reported inverse association between allergy and childhood ALL.