The undifferentiated carcinoma of nasopharyngeal type (UCNT) is highly prevalent in South East Asia countries and has intermediate incidence in Tunisia, where Epstein-Barr virus constitutes one of the key factors of oncogenesis. Our preliminary results, in 3 patients with UCNT, show an elevated rate of EBV antibodies and a latent infection (type II) (expression of LMP and absence of ZEBRA by immunohistochemical reaction) and a positive staining with EBERs probe by in situ hybridation (ISH) in all cases. These results confirm a close association between EBV and tunisian UCNT. Moreover, the use of HIS technique for detection of EBERs constitutes an additional and formal argument of this association.