Background and objective Glutathione S-transferase M1 (GSTM1) is an important phase II metabolic enzyme gene which involves metabolism of various carcinogens in human body. Many studies showed that GSTM1 genetic polymorphism was associated with lung cancer risk. The aim of this study is to investigate the relationship between GSTM1 genetic polymorphism and lung cancer risk among Han nationality population in Tianjin district. Methods GSTM1 genetic polymorphism was detected by melting curve analysis of SYBR green I real-time PCR assay. Two hundred and sixty-five histological confirmed lung cancer patients and 307 health controls were recruited in this case-control study and the relationship between GSTM1 genetic polymorphism and lung cancer risk was investigated. Results (1) The frequency of the GSTM1(-) in lung cancer and control groups was 56.6% and 57.0% respectively, and no significant difference was found between the distribution of the GSTM1(-) genotype in the two groups (χ2=0.831, P=0.362). (2) When considered the GSTM1(+) genotype as reference, there was no overall statistically increased lung cancer risk for carriers with the GSTM1(-) genotype adjusted by age, gender and smoking status (OR=0.840, 95%CI: 0.578-1.221, P=0.362). (3) The frequency of the GSTM1(-) genotype for squamous cell carcinoma, adenocarcinoma, SCLC and other histological types was 65.8%, 48.5%, 47.8% and 52.2% respectively, compared with the control group, no statistically increased lung cancer risk was observed (P>0.05). Conclusion No evidence is found between GSTM1 genetic polymorphism and lung cancer risk among Han nationality population in Tianjin district.