Plasmablastic lymphoma is a rare, highly aggressive lymphoma characterized by large lymphoid cells with immunoblastic or plasmablastic features, absent expression of CD45 and CD20, positivity for CD138, and monoclonal rearrangement of the immunoglobulin heavy chain gene. It was originally reported in oral cavity in the setting of underlying human immunodeficiency viral infection but may occur also in lymph nodes or extranodal sites after transplantation and, more rarely, immunocompetent patients. Herein, we report a case of PBL presenting as an ulcerated lesion of the tongue in an HIV-negative patient, 6 years after renal transplantation. To date, only rare cases of plasmablastic lymphoma presenting after solid organ transplantation have been reported. Although a reduction of immunosuppression and an aggressive chemotherapy were performed, the patient died after a few months because of septic and cardiovascular complications.