Study Objective. To evaluate the effectiveness and safety of laparoscopic and laparotomic management of ovarian tumors. Design. Retrospective analysis (Canadian Task Force classification II-2). Setting. University-affiliate hospital. Patients. Six hundred forty-one women with benign and malignant ovarian tumors. Interventions. Laparoscopy and laparotomy. Measurements and Main Results. Between January 1997 and December 1998, 493 (76.9%) ovarian tumors were treated laparoscopically and 138 (21.5%) by laparotomy. Criteria for laparotomy were high suspicion of malignancy and tumors larger than 10 cm that were technically too difficult for the laparoscopic approach. The mean size of tumors treated laparoscopically was 4.5 cm (range 1.1-11 cm) and by laparotomy 8.2 cm (range 3-20 cm). Mean operating times were 75.7 minutes (range 30-200 min) and 126 minutes (range 30-235 min), respectively, and mean blood loss was 193 ml (range 50-1200 ml) and 431 ml (range 50-2500 ml), respectively. Twelve laparoscopies were converted to laparotomy, six because of technical reasons such as severe adhesions, bleeding, or tumor size, and six for intraoperative suspicion of malignancy. Of the latter, four (66.7%) turned out to be ovarian carcinoma and two (33.3%) borderline tumors. Histologic evaluation clearly revealed predominance of functional ovarian cysts, endometriomas, and dermoid cysts in the group treated by laparoscopy, whereas ovarian carcinomas, large endometriomas, and serous cysts prevailed in the laparotomy group. Conclusion. With careful preoperative screening, the rate of laparoscopies for treatment of benign ovarian cysts can be increased.