Diffuse large B-cell lymphoma (DLBCL) is the most commonlymphoid neoplasm. Based on the increasing evidence for the associationbetween carcinogen-exposure-related cancer risk and xenobiotic genepolymorphisms, we have undertaken a case-control study on xenobioticgene polymoprhisms namely glutathione-S-transferase, GSTT1 andGSTM1 in Egyptian patients with a diagnosis of diffuse large B-celllymphoma.The purpose of the current study was to determine the frequency ofGSTT1 and GSTM1 genes polymorphism in fifty Egyptian DLBCLpatients and to clarify their role in susceptibility to DLBCL. To achievethis aim, GSTT1 and GSTM1 genotyping was tested by multiplex PCR.Forty age and sex matched healthy volunteers were included in thecurrent study as a control group. GSTT1 null genotype was detected in64% of patients. GSTT1 null genotype was significantly higher inpatients compared to controls and was associated with increased risk ofDLBCL. GSTM1 null genotype and dual null genotype were detected in44% and 34% of patients respectively and were not associated withincreased risk of DLBCL.