Ovarian remnant syndrome occurs in patients who have had attempted oophorectomy and part of the ovary was left behind. It often happens in patients who are undergoing total abdominal hysterectomy with bilateral salpingo-oophorectomy in the setting of severe pelvic adhesions. In those cases, the surgeon, to avoid injury to the ureter, which is not well visible, clamps gonadal vessels too close to the ovary and some ovarian tissue remains in the patient. The patient often experience severe, sharp unilateral pelvic pain that is cyclical in nature. On ultrasound there is often a cystic adnexal mass but lack of a mass does not rule out an ovarian remnant. Hormonal assays may also be helpful. Treatment is surgical but surgery for this condition may be overly difficult because the original surgery to remove the ovary was most likley difficult in the first place. Procedures to remove ovarian remnants should be performed only by highly qualified providers who are experienced in operating in the setting of severe adhesions. On a positive note, patients in whom ovarian remnant was successfully removed are almost always cured of their pain.