The urethral polyps in children are different from those in adults because the polyps usually originate at the proximal vermontanum, and are covered with transitional epithelium. A case of posterior urethral polyp in a child is reported herein. In this case, 5 years of age, the polyp was thought to be the cause of urinary tract infection (UTI) and histological findings revealed fibrous non-prostatic tissue. Transurethral resection of polyp was performed successfully.