Nasopharyngeal carcinomas (NPC) challenge clinicians and biologists in various fields including epidemiology, genetics, virology and immunology. These tumours have a striking geographical distribution. They are constantly associated with the Epstein-Barr virus (EBV) and contain a massive lymphocytic infiltrate. Their study has major implications especially at this moment while a pathological role of EBV is suspected in several other human epithelial malignancies (for example gastric, mammary and thyroid carcinomas). The North-South Workshop on Nasopharyngeal Carcinoma was held at the Institut Gustave-Roussy in early December 2003. Its main goal was to support the exchanges between clinical research on NPC in the South and basic research in the North. With regard to epidemiology and genetics, the main information was the possible existence of several susceptibility genes (including two of them on the 4p and 5p chromosomes). In virology, participants have emphasized the selection of peculiar EBV variants within the malignant cells and the expression of novel oncogenic viral proteins : LMP2 and BARF1. Cellular gene alterations also contribute to NPC development, especially inactivation of tumor suppressor genes located on the 3p chromosome. Therapeutic research was not forgotten. Hope of higher rate of cure relies on improved ballistic processes in radiotherapy (IMRT) and on the development of targeted therapeutics : induction of the lytic/productive viral cycle, gene therapy with conditional replicative adenoviruses, antitumor vaccination directed against the viral protein LMP2.