Complete duplication of the bladder and urethra is a very rare congenital anomaly which is diagnosed either shortly after birth or during early childhood. These rare malformations are usually seen by other concomitant anomalies, especially in the genital area, large intestine and skeletal system. Complete duplication often occurs in the coronal and sagittal planes and may emerge as complete or incomplete. We present a 6-year-old female patient who was admitted to Vasei Hospital in sabzevar, Iran (in 2015) with a urinary tract infectionin. Because of double urethra in the genital area, more diagnostic tests were conducted due to suspicion of congenital abnormalities of the urinary system. Sonography showed cystic mass on the left adjacent to the bladder. Computer scan with IV contrast showed duplication of the bladder connected to left ureter and the right ureter. To the best of our knowledge, so far, no female case is being reported with complete duplication of the bladder and urethra in Iran. The case of this patient is remarkable and unique both in terms of gender and complete bladder duplication.