This article reports on one patient with a double uterus, unilateral vaginal obstruction, with hemi-haematocolpos and ipsilateral renal agenesis. Early accurate diagnosis followed by the excision of the obstructing vaginal septum offers complete relief of symptoms, while preserving reproductive capacity. Unlike conventional excision of vaginal septum, we used resectoscope excision with cutting electrode under continuous pure distilled water irrigation. The postoperative course was uneventful, and haematocolpos and severe dysmenorrhoea disappeared. The resected vaginal area revealed re-epithelialization by hysteroscope follow-up one year after resection. With advancements in resectoscopic operation, evaluation and treatment of vaginal disorders in babies and virgins is very feasible.