Hodgkin lymphoma (HL) and nasopharyngeal carcinoma (NPC) are characterized by their association with Epstein–Barr virus (EBV) and an abundant infiltrate of reactive lymphoid cells. The presence of this lymphoid stroma may influence the effect of anti-viral immunotherapy. The interferon-inducible chemokine IP-10 has anti-neoplastic effects in several model systems mediated by T-cells expressing the CXCR3 chemokine receptor. Using in situ hybridization, it is shown that IP-10 is expressed in neoplastic cells of HL and correlates both with the mixed cellularity histotype and with EBV infection. IP-10 expression was also detected in tumour cells of most NPCs as well as in EBV-negative squamous cell carcinomas of the tongue. Thus, in carcinomas, IP-10 expression showed no correlation with EBV infection. Numerous CXCR3-positive lymphocytes were detected in the lymphoid stroma of HL and NPC, raising the possibility of a Th1-predominant immune response in these cases. In view of the proposed anti-neoplastic functions of IP-10 and CXCR3-positive lymphocytes, these findings are unexpected and raise the possibility that endogenous IP-10 expression in the context of human tumours may not exert the anti-tumour effects ascribed to it by in vitro experiments. Copyright © 2005 Pathological Society of Great Britain and Ireland. Published by John Wiley & Sons, Ltd.