The necessity for improved technic in repair of complete laceration of the recto-vaginal septum is emphasized by an occasional failure due to infection from the rectum, which may enter the wound when imperfectly approximated or by contamination of the sutures primarily and deeper tissue secondarily. Catgut may absorb too soon and allow the parts to separate. Silk sutures cause pain, ulceration, cicatrization and may even require removal through the speculum, all of which is undesirable. To overcome these objectionable features I have devised a very simple flap operation. It consists in splitting the recto-vaginal septum, dissecting the lower end of the rectum from the vagina and drawing its anterior wall down through and external to the anus. In this way it converts a complete tear of the perineum into an incomplete laceration. The line of incision (black line, Fig. 1) starts on the external side of the sphincter dimple at