Epstein-Barr virus (EBV) has been linked etiologically to infectious mononucleosis, some non-Hodgkin as well as Hodgkin lymphomas, and lymphoepithelioma-like carcinomas. Moreover, various EBV antigens have been identified by a variety of techniques in a number of visceral carcinomas including breast, prostate, colon and lung primaries. We have now demonstrated by immunohistochemistry the presence of EBV nuclear antigen-1 (EBNA-1) in 4 of 15 cases of conjuntival squamous carcinomas and related dysplasias. At present, there is no significant evidence linking etiologically EVB to this type of tumor and dysplasia. However, our findings merit further investigation given the growing evidence that EBV may enhance proliferation and aggressiveness of tumor systems as well as the immortalization of non-neoplastic cells.