Lymphoepithelioma-like carcinoma, an uncommon epithelial tumor, has been described as being closely associated with Epstein-Barr virus (EBV) infection in many organs, especially the nasopharynx. We experienced 23 cases of lymphoepithelioma-like carcinoma arising in the lung from 2498 lung cancer patients in the Cancer Registry of our hospital. Seven patients were male and 16 were female. All patients were Chinese. Their ages ranged from 42 to 80 years. Six patients were smokers and 17 were nonsmokers. The tumor sizes ranged from 1.2 to 11.0 cm. All tumors showed the typical syncytial growth pattern of undifferentiated epithelial cells with a significant CD8+ T-lymphocyte reaction. EBV serology revealed prior infection in all 15 serum-available patients, all of whom were also found by in situ hybridization to have the virus genome. In addition, the higher the EBV serology titer, the larger the tumor size and the higher the staging would be. EBV viral capsid antigen IgG level remained elevated despite response to therapy. Nearly all cases had bcl-2 oncoprotein expression, but the detection rate of latent membrane protein-1, p53, and c-erb B-2 expression was extremely low. The encouraging chemotherapy response for advanced stage disease is also discussed.