Urachal xanthogranuloma is an extremely rare disease. An 18-year-old male presented with lower abdominal pain, hematuria, and dysuria. An urachal mass with bladder invasion, which was suspected to be an urachal carcinoma or abscess, was observed on computed tomography. Exploratory laparotomy, excision of the urachus, and partial cystectomy was performed by way of a lower midline incision. Histopathologic examination identified the mass as an urachal xanthogranuloma.