Paraffin sections of an undifferentiated salivary gland carcinoma of lymphoepithelioma type, arising in a white (Greek) patient and confirmed by immunohistochemistry, were examined for the presence of Epstein-Barr virus (EBV), using in situ hybridization to detect EBV-specific EBER1 message. Epstein-Barr virus was detected in malignant epithelial cells, but was not found in lymphoid stroma or in residual benign salivary epithelium. These results confirm the existence of an association between EBV and tumor cells of undifferentiated carcinoma of parotid gland. This is the first demonstration of EBV in a salivary gland lymphoepithelioma arising in a non-Eskimo, white patient. This finding suggests that the association of EBV with undifferentiated salivary gland carcinoma may exist in geographic regions remote from Greenland.