Inherited polymorphisms in DNA repair genes may contribute to genetic susceptibility to cancer. XPA, XPC and XPD all encode proteins that are part of the nucleotide excision repair pathway. In a nested case-cohort study, we have investigated the occurrence of lung cancer in relation to commonly occurring polymorphisms in XPA, XPC and XPD. Among 54,220 members of a Danish prospective cohort study, 265 lung cancer cases were identified and a sub-cohort comprising 272 individuals was used for comparison. We found that XPA A23G and XPC Lys939Gln polymorphisms may be risk factors for lung cancer and evidence that positive interactions between the polymorphisms in XPA/XPD and XPC/XPD may occur.