A 77-year-old man presented complaining of generalized edema for 1 week. He had hypertension and polycystic kidney disease (PKD), which was diagnosed 45 years ago. Blood and urine tests showed low serum albumin (2.3 g/dL) and severe proteinuria (6.38 g/day). Abdominal computed tomography revealed multiple cysts with thin wall calcification in the left kidney, and several cysts in the right kidney and the liver (Fig. 1). Ultrasonography-guided percutaneous renal biopsy for the right kidney revealed focal segmental glomerulosclerosis (Fig. 2). The patient was prescribed diuretics, an angiotensin receptor blocker, aspirin, statin, a β blocker, and an aldosterone antagonist. One month after starting the medicines, he showed improved symptoms and laboratory findings (serum albumin, 3.2 g/dL; urine albumin excretion, 654.8 mg/g creatinine), which further improved after another 3 months (serum albumin, 3.8 g/dL; urine albumin excretion, 128.4 mg/g creatinine).