Laparoscopic approaches to giant ovarian cysts, particularly in adolescents, have critical management concerns as follows: risk of malignancy, risk of cyst rupture, and limited working space. A 15-year-old girl presented with a giant (N25 cm) ovarian serous cyst adenoma containing 7 L of fluid. At open laparoscopy, a giant, entirely cystic, smooth mass originating from the right ovary and lying between the symphysis and the xiphoid was observed. After intraabdominal fluid aspiration, open conservative cystectomy was performed, avoiding spillage. The patient made an uneventful postoperative recovery and was discharged on the second postoperative day. To our knowledge, this is the largest ovarian cyst treated conservatively in an adolescent. Minimal access surgery, laparoscopy and open cystectomy, can be safely proposed in this group of patients. Conservative surgery should always be evaluated for preservation of ovarian function in cases of giant ovarian cysts in adolescents. Published by Elsevier Inc.Large ovarian cysts in adolescents may present as a challenge to gynecologists. The patient's age, menstrual status, the size and structure of the cyst, risk of malignancy, and symptoms are critical in choosing treatment strategies.Laparoscopy represents the gold standard approach for the treatment of ovarian cysts. In the adolescent population, laparoscopy may be difficult, particularly when the cysts' sizes extend to the umbilicus because of limited working space, risk of rupture, and perioperative problems related to cardiorespiratory function [1].Currently, many treat large ovarian cysts in adolescents by ovariectomy, whereas a few try laparoscopic cystectomy after aspiration of the cyst (blindly or under ultrasound [US] guidance). These techniques do not rule out the risk of spillage and do not allow the surgeon to inspect the peritoneal cavity and the posterior cyst wall properly, which is considered a very important precaution to take before performing a cystectomy [2].We present a case of a 15-year-old virgin girl with a giant ovarian cyst that was treated by minimal access surgery, laparoscopy and open cystectomy.