Virus associated hemophagocytic syndrome (VAHS) are a heterogeneous group of disorders in which viral infection is associated with a proliferation of hemophagocytic histiocytes through the reticuloendothelial system. We report the case of a 21-year-old Korean man who presented to us with high fever, marked hepatosplenomegaly, severe hepatic dysfunction, coagulopathy, pancytopenia and marked panhypogammaglobulinemia. Bone marrow aspiration and biopsy showed histiocytes proliferation with active phagocytosis of red cells and neutrophils. Primary Epstein-Barr (EB) viral infection at presentation was confirmed by the presence of IgM antibody to viral capsid antigen (VCA) with absence of antibody to EB viral nuclear antigen (EBNA). A liver biopsy performed one month after the presentation showed erythrophagocytic histiocytes within the sinusoids. EB virus was demonstrated in the liver biopsy tissue by DNA PCR method, and EBER mRNA in situ hybridization.