Urologic manifestations of neurofibromatosis type 1 are rare. The most common urologic area of involvement has been the urinary bladder. Prostate involvement in generalized neurofibromatosis has been noted previously in only 10 patients, 3 of whom were adults. Of these 3, 1 had a neurofibroma, 1 had a malignant schwannoma, and 1 patient died before tissue diagnosis could be obtained. The patient discussed in this report is the second known adult patient with biopsy-proven neurofibroma of the prostate gland. In addition, this is the first reported use of endorectal magnetic resonance imaging of the prostate to localize and specify the extent of neurofibromas in these patients.