The correlation between cooking oil fumes, containing relatively higher amounts of heterocyclic amines, and female lung cancer has been revealed. The association of genetic polymorphisms of CYP1A2 and NAT2, two major enzymes responsible for the metabolism of heterocyclic amines, with lung cancer has been investigated with inconclusive results. In this study targeted on never-smoking population with 162 lung cancer patients and 208 non-cancer controls, while the distributions of CYP1A2 phenotypes in lung cancer patients were comparable to that in controls, NAT2 fast acetylators had an OR of 2.44 (95% CI 1.40-4.23, P=0.002) and 2.56 (95% CI 1.37-4.80, P=0.003) for lung cancer in overall and female cases, respectively, but not in males. These results suggested never-smoking females with NAT2 fast acetylator were more prone to lung cancer and reflected the possibility that exposure to heterocyclic amines may contribute to the female lung cancer development in Taiwan.