Objectives: Most of human cancers may result from exposure to environmental carcinogens, and individual effectiveness in the detoxification of these chemicals will influence susceptibility to malignant disease. Glutathione S-Transferases(GSTs) enzymes are involved in the detoxification of active metabolites of many carcinogens from tobacco smoke and may be important in modulating susceptibility to smoke-related cancer. The purpose of this study is to determine the polymorphism of GSTM1, GSTT1, and GSTP1 in control group and head and neck squamous cell carcinoma group of Korean, and to investigate the effect of GSTs polymorphism on the risk of head and neck cancer. Materials and Methods: A hospital-based case-control study was performed with a group of 133 control individual and 136 head and neck squamous cell carcinoma patients. The polymorphisms of GSTs were analysed using polymerase chain reaction in GSTM1 and GSTTl, and polymerase chain reaction-restriction fragment length polymorphism in GSTP1. Results: The relative risk (odds ratio) of GSTM(-) genotype was 1.14(95% CI, 0.70-1.85) compared to GSTM1(+). The odds ratio of GSTTl(-) genotype was 0.91(95% CI, 0.55-1.50). In old age($65$) group, the odds ratio of GSTT1(-) genotype was 5.2(95% CI, 1.53-17.89). The GSTP1 Val/Val genotype conferred a 1.7-fold risk(95% CI, 0.40-7.34) of head and neck cancer compared with GSTP1 Ile/Ile genotype. Among the combined genotypes of GSTs, GSTM1(-)/GSTT1(+)/GSTP1 Val/Val and GSTM1(-)/GSTTl(-)/GSTP1 Ile/Val genotypes conferred a 2.6-fold and 1.3-fold risk(95% CI, 0.24-14.15 and 0.43-3.14) compared with the GSTM1(+)/GSTTl(+)/GSTP1 Ile/Ile genotype, respectively. Conclusion: Polymorphism of GSTs might modulate susceptibility to head and neck cancer in Korean population. The genotype of GSTP1 Val/Val and combined genotypes of GSTM1(-)/GSTT1(+)/GSTP1 Val/Val, and GSTM1(-)/GSTT1(-)/GSTP1 Ile/Val might be important risk factors to determine the individual susceptibility to head and neck squamous cell carcinoma.