Plasmablastic lymphoma (PBL) was first reported in 1997 as a non-Hodgkin’s lymphoma with a poor prognosis that occurred in the oral cavity of some human immunodeficiency virus (HIV) -positive patients. In 2008, it was added to the WHO classification as a type of aggressive B-cell lymphoma that can also occur in extranodal sites of elderly or immunocompromised patients. As half of the cases are related to Epstein-Barr virus (EBV) infection and categorized as EBV-associated lymphoproliferative disorders. We report a case of EBV-positive PBL that occurred in the mandibular gingiva of an HIV-negative patient. The patient was an 87-year-old man with a mass in the gingiva surrounding the second left mandibular molar. A biopsy revealed that the lesion was EBV-positive PBL. Serologically, HIV antibody was negative. The patient underwent radiation therapy (50 Gy), which led to a completely positive response. After treatment, no recurrence was detected. Three years one month after treatment, dehydration led to a decrease in the level of consciousness and the resulting deterioration of general condition, and the patient died one month later.