We presented the clinical data of one patient with renal cell carcinoma associated with idiopathic thrombocytopenic purpura in this case report. We reported a 56-year-old man who presented with petechiae and ecchymoses. Laboratory studies showed the platelet count of 2 × 109/L and an abdominal computed tomography (CT) scan revealed tumors in the right renal. There were purpura on the legs and cough without abdominal pain and melena at this time. Idiopathic thrombocytopenic purpura was diagnosed according to the clinical symptoms and laboratory test. The patient received radical nephrectomy for renal carcinoma, and his idiopathic thrombocytopenic purpura was cured after the surgery. Pathological biopsy confirmed it was renal clear cell carcinoma. The patient has been followed up for more than 3 months after surgery, and the ecchymoses had not been recurred and the patient's thrombocytopenia was recovered. Idiopathic thrombocytopenic purpura associated with kidney cancer is rare. The patient in this case report was treated with radical nephrectomy, and the effectiveness of idiopathic thrombocytopenic purpura was satisfactory.