Background: In this case-control study, we aimed to investigate the relationship between the methylenetetrahydrofolate reductase (MTHFR) C677T polymorphism and lung cancer. Materials and Methods: Total 200 individuals including 100 patients with lung cancer and 100 controls were analyzed. Genotyping of MTHFR C677T was performed using PCR and RFLP methods. Results: The majority of the patients were men and 90% were smokers. We found that the risk ratio for development of LC was 13-times higher in smokers compared with non-smokers between patient and control groups in our study (OR:13.5, 95% CI:6.27-29.04, p:0.0001). Besides, the risk ratio for development of LC was nine times higher in individuals with cancer history in their family than those without cancer history (OR:9.65, 95% CI:2.79-33.36; p:0.0001). When genotype distributions and allele frequencies were analyzed in the study groups, no significant difference was apparent (chi(2):0.53, p=0.76). In addition, no correlation between genotypes of MTHFR C677T polymorphism and histological type of LC was found (chi(2):0.99, p=0.60). Conclusions: These results suggest that there was no association between the MTHFR C677T polymorphism and lung cancer in the Turkish population.