Introduction: Post-transplant lymphoproliferations (PTL) are a severe complication of solid organ transplants. Their locations can be extra-nodal. Observation: The diagnosis and management of a non-Hodgkin's plasmablastic lymphoma of mandibular localization affecting a 66-year-old kidney transplanted patient are reported here. Comment: The main risk factors for non-Hodgkin lymphoma are immunosuppression and infection with Epstein-Barr virus. Clinical and radiographic examinations, which are not specific, must be supplemented by a histological examination. Treatment which is not consensual will most often consist of a reduction in immunosuppression coupled with chemotherapy. Conclusion: Despite a constant evolution in the incidence and clinical picture of post-transplant lymphomas, the role of the dentist remains essential in the early detection of lesions.