Posttransplant lymphoproliferative disorder is one of the most important complications of solid-organ transplant in terms of malignancy. Here, we report a case of Epstein-Barr-virus-negative posttransplant lymphoproliferative disorder of T-cell type, involving the lung, in a renal transplant recipient. A 23-year-old woman received a living-related renal transplant in 2002. She presented with a 6-month history of weight loss, malaise, night sweats, and lymphadenopathy 6 years after the transplant. Chest radiograph showed miliary opacities. We performed a biopsy of the submandibular mass and computed-tomography-guided transthoracic needle biopsy of the lung. Pathological investigation of lymphadenopathy and lung were inconsistent with posttransplant lymphoproliferative disorder of T-cell type. After the diagnosis of posttransplant lymphoproliferative disorder, her immunosuppressive regimen was modified, and she was treated with cyclophosphamide, doxorubicin, vincristine, prednisolone, ifosfamide, carboplatin, and etoposide chemotherapies, which resulted in partial remission. Posttransplant lymphoproliferative disorders may be seen as an atypical presentation; the differential diagnosis should be thought of pulmonary infiltrates in renal transplant recipients. © Başkent University 2011.