Idiopathic thrombocytopenic purpura associated with renal cell carcinoma is relatively rare. We report the case of a 48-year-old woman with massive renal cell carcinoma, measuring approximately 20 × 14 × 14 cm, who presented with severe thrombocytopenia: platelet count, 2000 cells/μL. After confirming normal bone marrow, she received high-dose dexamethasone and intravenous gamma globulin, which raised the platelet count to normal levels. She then underwent left radical nephrectomy. The pathological examination showed chromophobe renal cell carcinoma. After the resection, the platelet count was maintained within the normal range without any treatment. The current case is the first report of chromophobe renal cell carcinoma causative of severe idiopathic thrombocytopenic purpura.