A 58-year-old man from Brazil was followed as an outpatient with asymptomatic macroglobulinemia and idiopathic thrombocytopenic purpura (ITP). Abdominal enhanced computed tomographic (CT) scan for elevated liver enzymes revealed a left renal tumor. The tumor was in the middle outer left kidney, measured 18 mm in diameter, was discovered in its early phase, and appeared half exophytic. After investigations, the patient was diagnosed with left renal cell carcinoma associated with ITP. His preoperative platelet count was 10,000/μl ; five days of intravenous gamma globulin therapy with high-dose dexamethasone increased the platelet count to 76,000/μl just before operation. Laparoscopic left partial nephrectomy was performed successfully using the retroperitoneal approach. The renal artery was clamped and the tumor excised with an adequate margin. Renal parenchymal repair was completed using running sutures. Ischemia time was 16 minutes. There was no severe oozing of blood intraoperatively. The platelet count decreased to 15,000/μl on postoperative day three (POD 3), and there was oozing of blood around the retroperitoneal drain tube. The bleeding stopped after administration of platelet transfusion. The patient was discharged on POD 9. The histopathological diagnosis was clear cell carcinoma, and surgical margins were negative.