Epstein-Barr virus (EBV) was discovered in 1964 by using electron microscopy to visualize the viral particles in B lymphocytes from a Ugandan child with a tumor of the jaw, which is now known as endemic Burkitt lymphoma (eBL) [1]. Thus, EBV was the first recognized human cancer virus. Four years later, EBV was determined to be the major cause of infectious mononucleosis [2]. Researchers considered multiple sclerosis (MS) to be an infectious disease as long ago as 1894 [3], but the role of EBV in the pathogenesis of MS was controversial until very recently [4], [5]. Several years after the discovery of EBV, serologic studies implicated this virus as a potential cause of Hodgkin lymphoma [6]. An “incubation period’’ of 3 years for Hodgkin lymphoma after infectious mononucleosis was described by Hjalgrim et al. [7]. A link between EBV and nasopharyngeal carcinoma (NPC) was suggested as early as 1966 by testing individuals from the United States and Africa for serum antibodies against an EBV antigen [8]. EBV antibodies were found in 85 % of patients with NPC (33/39) and 56 % of patients with Burkitt lymphoma (31/55) as compared with 10 % of healthy blood donors (8/82). eBL, Hodgkin lymphoma, NPC, gastric cancer, MS, and several collagen vascular diseases with ties to EBV are discussed in this review.