Neurofibromatosis is a hamartomatous disorder of neural crest derivation characterized by cutaneous pigmentation and tumor formation in various tissues. Visceral involvement is typically insidious, progressive, and difficult to treat. Plexiform neurofibroma of the urinary tract is rare. involvement of nearly every genitourinary structure by these lesions has been reported, with the bladder being most commonly involved. In part due to the small number of patients seen at any one institution and the highly variable location and extent of this disease process, a plan for management of individuals with genitourinary neurofibromatosis has not been proposed. In an attempt to define specific goals in treatment of such patients, we reviewed our population of 260 pediatric patients with type I neurofibromatosis. We present our series of 5 patients with complex genitourinary lesions and describe specific management principles. (C) 1997, Elsevier Science Inc.