To assess the efficacy of operative laparoscopy to confirm the diagnosis of benign adnexal masses, and treat the lesions. DESIGN: Consecutive patients evaluated for this indication between January 1989 and December 1993, who met the inclusion criteria. SETTING: The Jan Palfijn General Hospital, Antwerp, Belgium, and the Department of Obstetrics and Gynecology, University of Varese, Varese, Italy. PATIENTS: One hundred twenty-one women with a clinical, biochemical, and ultrasound diagnosis of benign adnexal mass. INTERVENTIONS: Operative videolaparoscopy was carried out in all patients using the carbon dioxide or argon laser, electrical, or mechanical means. MEASUREMENTS AND MAIN RESULTS: Depending on the patient's age and the appearance of the adnexal mass aspirate, biopsy, cystectomy, or adnexectomy was performed. The conversion rate to laparotomy was 2.4%. A pathologic diagnosis was made in all cases. In this series no malignancy was encountered. CONCLUSION: Operative laparoscopy is safe and effective for treating adnexal masses provided that the preoperative diagnosis indicates that the lesions are benign.