Primary immunodeficiency (PID) is an inherited disorder of impaired immunity. Most patients with PID present with recurrent and/or severe infection. The type of infection is strongly associated with the type of PID. In general, bacterial infection is seen in patients with antibody deficiencies and phagocytic disorders, and viral and fungal infection is seen in those with T cell deficiencies. Herpesviruses are DNA viruses including herpes simplex (HSV)-1/2, varicella zoster virus, cytomegalovirus (CMV), Epstein-Barr virus (EBV), and human herpes virus (HHV)-6/7/8 in human. Severe herpesvirus infection is observed in patients with T cell deficiency, particularly severe combined immunodeficiency (SCID). CMV infection associated with SCID may have frequently fatal outcome even with any treatment. Interestingly, some herpesvirus infection is found in specific PID. Severe HSV encephalitis is observed in patients with toll-like receptor (TLR)-3 signaling disorder. Severe and fatal EBV infection is observed in patients with X-linked lymphoproliferative syndrome (XLP) and Chediak-Higashi syndrome. Recent molecular advances disclosed that severe EBV infection was found not only in XLP but also in other PID including CD27, ITK, MAGT1, STK4, Coronin 1A deficiency. Here I show PID predisposing to EBV, that is inherited EBV-associated disorder.