We identified haplotypes of several genes that were significantly associated with childhood ALL, including ABCB1, ARNT, CYP2C8, CYP1A2, CYP1B1, and IDH1. In addition, we observed significant interactions of identified risk haplotypes with a number of self-reported household chemical exposures, including use of paints and indoor insecticides. This evidence concerns the gene CYP2C8 and acute lymphoblastic leukemia.