Lung cancer is a common cause of cancer-related death. The link between risk of lung cancer susceptibility and genetic polymorphisms in metabolic enzymes is well documented. In this study, the relationships between lung cancer susceptibility and polymorphisms in the phase I metabolic enzyme genes CYP1A1, CYP2D6, and CYP2A6 were investigated. Genomic DNA was isolated from the peripheral blood of 201 healthy controls and 168 lung carcinoma patients from the Han ethnic group of Hunan Province in Central South China. Polymorphisms of the investigated genes were analyzed using polymerase chain reaction-restriction fragment length polymorphism (PCR-RFLP) and two-step allelic-specific PCR assays. No significant differences were found between the frequencies in cases and controls for the genotypes wild-type (WW), heterozygous mutant, or homozygous mutant; for CYP1A1 or CYP2D6; or for the genotypes WW, heterozygous deletion, or null genotype for CYP2A6. The three-locus model (CYP2A6/CYP1A1/CYP2D6) had a maximum test sample accuracy that was significant (P < 0.001) with a cross-validation consistency of 10. These results indicated that the three-order interaction of CYP2A6, CYP1A1, and CYP2D6 polymorphisms might increase genetic susceptibility to lung cancer. We report the involvement of a three-order interaction between CYP1A1, CYP2A6, and CYP2D6 polymorphisms in lung cancer risk in people in Central South China, although no relationship between lung cancer risk and individual gene polymorphisms was found.