We present a case of a 16-year-old boy with a primary clear cell adenocarcinoma of the prostatic utricle. The patient presented with a 6-month history of intermittent, nonpainful, gross hematuria and an associated right renal agenesis. Radiographic studies revealed the presence of a solid and cystic mass between the bladder neck and the cranium of the prostate. Serum tests, including prostate-specific antigen, carcinoembryonic antigen, CA-19-9, and human chorionic gonadotropin, were performed and found to be within normal limits. A surgical resection of the mass including prostate and seminal vesicles was performed. Grossly, a polypoid exophytic tumor was present at the prostatic utricle. Histologically, the tumor shows the classical clear cell morphology reminiscent of the so-called mesonephric adenocarcinomas. At clinical follow-up, the patient is alive and well 18 months after surgical resection. The present case highlights an unusual phenomenon of the development of an unusual form of adenocarcinoma in an adolescent.