Imperforated hymen, vaginal atresia or high transverse vaginal septum are caused by incomplete vaginal canalization. The infant may be present with distention of the vagina and the uterus with glandular secretions stimulated by maternal estrogens, known as hydrometrocolpos. We report two cases of hydrometrocolpos. In the first case, distal vaginal atresia with cystovaginal fistula was revealed by a contrast fluoroscope through the percutaneous catheterization. In the second case, urogenital sinus was detected by a fistulogram through a single orifice in the genital area. We decompressed the cystic mass by ultrasonogram guided aspiration, promptly at birth, then achieved the transient drainage of cystic fluids by percutaneous catheterization.