The relationship between glutathione S-transferases (GSTs) M1, T1 genotype and childhood acute lymphoblastic leukemia (ALL) was investigated. GSTM1 and GSTT1 genotypes in genomic DNA from 67 children with ALL and 146 healthy controls were analyzed by using the multiplex polymerase chain reaction (PCR). The frequencies of GSTM1, M1-T1 null genotypes in ALL children were significantly higher than in the healthy controls (76.12% versus 52.74%, OR=2.856, P<0.001; 50.74% versus 24.66%, OR=3.148, P<0.001, respectively). However, there was no significant relationship between GSTT1 null genotype and ALL of children (61.19% versus 49.32%, OR=1.621, P>0.05). It was suggested that GSTM1 null genotype might be a risk genotype of childhood ALL, while there as no correlation between GSTT1 null genotype and childhood ALL.