T cell non-Hodgkin lymphoma is characterized by uncontrolled cellular proliferation of immature malignant clones. HIV-associated T cell non-Hodgkin lymphoma comprises a heterogeneous group of lymphoproliferative neoplastic entities classified according to morphological, immunological, genetic and clinical features. Extranodal T cell non-Hodgkin lymphoma of the oral cavity is uncommon. A case is presented with extranodal T cell non-Hodgkin lymphoma as an initial sign of HIV-infection. The characteristics of HIV-associated non-Hodgkin lymphoma are discussed.