Neurofibromatosis (NF) is a genetic disorder of the nervous system that primarily affects the development and growth of neural cell tissues. This disorder is characterized by the development of various tumors, including neurofibromas, neuroniomas, malignant and benign peripheral nerve sheath tumors, and meningiomas. Accompanying skin changes and bone deformities are also common in NF. However, genitourinary involvement in NF is a rare condition, and penile enlargement has been reported only in a few males with plexiform NF. We report a 6-year-old boy with chronic renal failure associated with plexiform neurofibromas of the bladder and prostatic urethra which led to urinary obstruction and macrogenitalia due to genitourinary NF.