Fibroepithelial polyp of the ureter is a rare benign neoplasm of mesodermal origin. It is an extremely rare cause of hydronephrosis in children. It usually causes partial ureteral obstruction without loss of renal function. The preferred treatment is endoscopic or surgical resection of the polyp with preservation of the renal unit. The authors present an adolescent patient with a nonfunctioning left hydronephrotic kidney caused by complete ureteral obstruction caused by a giant fibroepithelial polyp of the distal ureter. This is an extremely rare presentation and outcome of this benign ureteral neoplasm with resultant loss of renal unit. (C) 2004 Elsevier Inc. All rights reserved.