Case Study: Renal vein thrombosis in adults can occur in association with or as a consequence of severe nephrotic syndrome, renal cell carcinoma, trauma, infection, and a variety of systemic hypercoagulable states. A case of a 48-year-old male was nephrotic-range proteinuria due to membranous nephropathy. He was treated with steroid and cyclophosphamide but no response. At his monthly clinic visit, the patient complained of dyspnea and oliguria. In labotory findings, serum creatinine 4.75 mg/dL, BUN 69.3. Hb 10.0. He was recived emergency hemodialysis and checked CT scan. CT scan shows huge thrombosis in inf. Vena cava and bilateral renal vein. Anticoagulant therapy was started and IVC filter inserted. Renal function was improved with resolution of symptoms.