ALL is the most frequent cancer among children. ALL may be caused by the carcinogenic effect of the environment modified by a series of genes. These genes explain variability in cancer susceptibility. This study examined the relation between genetic polymorphisms GSTM1 & CYP1A1 & susceptibility to childhood ALL by using genotyping approach. 50 patients with 30 controls were selected; results suggest GSTM1 null genotype may be considered as a risk factor while CYP1A1 may not be considered.