We report the resection of a vaginal septum while preserving the virginity of a 12-year-old girl with Herlyn-Werner-Wunderlich Syndrome (HWWS) having a didelphys uterus, obstructed hemivagina, and an ipsilateral renal agenesis with follow-up at 18 months. Successful resection of the vaginal septum with conservation of the hymenal ring and complete drainage of both the hematocolpos and the hematometra were achieved. Cyclic dysmenorrhea and pelvic pain were completely resolved on follow-up visits at 4, 6, and 18 months. Office hysteroscopy performed during the last follow-up visit revealed a patent vaginal vault without evidence of adenosis or recurrence of the vaginal septum. Vaginoscopy is a safe, convenient, and efficient diagnostic and therapeutic modality that can be used in the management of patients with an obstructed hemivagina. It maintains the patient's virginity and it is useful in patients with a restrictive vaginal opening or narrow vaginal canal. Furthermore, the hysteroscopic excision of the vaginal septum offers minimal risk of recurrence of the septal defect.