This prospective study was conducted to assess the feasibility of laparoscopic cystectomy of an intact adnexal cyst performed inside a water proof endoscopic bag, aiming to avoid intraperitoneal spillage in case of cyst rupture. 102 patients were recruited. Two of them were pregnant. In 8 of the patients the lesions were bilateral, adding up to a total of 110 cysts involved in our study. The endoscopic sac did not rupture in any case. Mean diameter of the cysts was 5.7 cm (range: 2.3-10.5 cm). In 75/110 (68.2%) cases, cystectomy was completed without rupture, whereas in the remaining 35/110 (31.8%) cases the cyst ruptured. Minimal small spillage occurred despite every effort only in 8/110 (7.2%) cases with large (>8 cm) cystic teratomas. There were no intraoperative or postoperative complications. We concluded that laparoscopic cystectomy in-a-bag of an intact cyst is feasible and oncologically safe for cystic tumors with a diameter < 8 cm. Manipulation of larger tumors with the adnexa into the sac may be more difficult, and in such cases previous puncture and evacuation of the cyst contents should be considered.