A 30-year old female who initially had typical endometriosis treated according to a standard regimen later developed numerous highly vascular endometrial polyps on the vagina, cervix, ureter, serosal surfaces of the uterus, pouch of Douglas (POD) and other areas of pelvic peritoneum as well as the endometrium 8 months after withdrawal of treatment with Zoladex gonadotrophin releasing hormone (GnRH) agonist used for treatment of this disease. We postulate that these polyps developed as a rebound phenomenon upon withdrawal of Zoladex. We believe this is the first report of this complication following use of GnRH analogue.