Objective: To study the relationship between one polymorphism in the promoter of the DNA repair gene XPA and the susceptibility to lung cancer. Methods: Genotypes were determined by the PCR-restriction fragment length polymorphism (PCR-RFLP)method in 310 histologically-confirmed lung cancer cases and 341 age and sex frequency-matched cancer-free controls. Results: The XPA A23G genotype frequencies were 27.1％ (AA), 42.9％ (AG), and 30.0％ (GG) in case patients and 21.1％ (AA), 52.8％ (AG),and 26.1％ (GG) in control subjects. Multivariate logistic regression analysis revealed that individuals carrying at least one 23G variant allele (AG + GG genotypes) had a significantly decreased risk for lung cancer (adjusted OR = 0.66; 95％ CI = 0.44- 0.98) compared with the wild-type genotype (23AA). Stratified analysis showed that the protective effect was more evident in subjects with a family history of cancer. Conclusion: These results suggest that the XPA A23G polymorphism may have a role in lung cancer susceptibility in this study population.