Kaposi's sarcoma occurs in higher rates in the setting of immunosuppression, especially in patients with acquired immunodeficiency syndrome (AIDS), immunosuppressive therapy or posttransplantation, commonly involving the skin, visceral, oral cavity or respiratory tract. Of the de novo malignancies in transplantation patients, the incidence of Kaposi's sarcoma is increasing steadily. We report a case of a 37-year-old male patient who was diagnosed with Kaposi's sarcoma 16 years after his first renal transplantation and 5 months after his second transplantation. He presented with lymphoproliferative lesions in the mediastinum and supraclavicular area without showing any typical cutaneous lesions. Diagnosis was confirmed by gun biopsy of the enlarged axillary lymph nodes. Tacrolimus, the initial immunosuppressive drug, was tapered while sirolimus therapy and chemotherapy with vincristine was initiated. The enlarged lymph nodes decreased in size and the patient has been treated with vincristin and conversion of tacrolimus to sirolimus.