A case of patent urachus was presented in this paper and briefly discussed regarding to the diagnostic method and treatment. A 1-month-old female infant was admitted to our hospital because of granulomatous mass and serous discharge from the umbilicus. As a result of fistulography, the fistula was found from the umbilicus toward the apex of the bladder. The complete excision of the urachus was performed for the therapy. Pathological features of the fistula showed granulation tissue with the inflammatory response characterized by cellular infiltration, fluid exudation and degeneration. The tubulal structures lined by transitional epithelium, which were suspected to be originated from the urachus, were seen in the deep portion.
