The endorectal advancement flap is an option in the treatment of rectovaginal fistulas. The patient in this video is a 42 year female with a 10 year history of Crohn's disease. After drainage of an abscess in her rectovaginal septum one year ago, she developed a rectovaginal fistula with chronic drainage of stool from her vagina. A seton was placed to control sepsis followed by a series of Remicaide treatments. The seton was subsequently removed but the fistula persisted. The endorectal advancement flap is performed under general anesthesia with the patient in the prone position. The anus is effaced and the mucosa injected with local anesthetic. A partial thickness flap of mucosa and muscle with a wide base is mobilized to a level above the fistula. The portion of rectal mucosa containing the fistula is resected. The vaginal wall is plicated to seal the vaginal opening. The flap is secured to the anoderm ensuring adequate length with no tension using absorbable sutures.