Autosomal dominant polycystic kidney disease (ADPKD) is an inherited disorder characterized by the development and growth of cysts in the kidneys. Non-nephritic-range proteinuria is a common presentation in ADPKD patients; however, nephrotic syndrome is a rare coincidence. A 52-year-old man is described who was diagnosed with secondary amyloidosis with ADPKD. To our knowledge, this is the first case of amyloidosis associated with frequently infected renal cysts. Patients with ADPKD who show massive proteinuria should be investigated in terms of concomitant glomerular disease.