Among 39 posttransplant lymphoproliferative diseases (PTLD) in a cohort of 450 pediatric liver transplant recipients, 3 had a malignant lymphoma, unresponsive to arrest of immunosuppression and to gancyclovir, interferon, and anti-interleukin 6 antibodies. Lymphoma appeared 20, 46, and 96 months posttransplantation and 16, 43, and 90 months after primary Epstein-Barr virus infection. In one case, the patient had histological progression from plasmacytic hyperplasia PTLD, concomitant with symptomatic primary infection, to Burkitt-like lymphoma 43 months later. These three patients received five courses of chemotherapy, after a cyclophosphamide, doxorubicin, vincristine, and prednisone regimen for Burkitt-like or LH 89 scheme for Hodgkin-like PTLDs. Chemotherapy was well tolerated, and all three were free of disease and without immunosuppression 19, 14, and 4 months after chemotherapy. In Burkitt-like or Hodgkin-like PTLDs, immunomodulatory or antiviral drugs were inefficient. Chemotherapy is indicated and can be safely and successfully used. Long-term arrest of immunosuppression seems feasible without graft rejection.