Abstract： Background Laparoscopy has been accepted for years as a management of benign ovarian tumors. The aim of this study was to estimate the feasibility and safety of laparoscopy in diagnosis and management of adnexal masses.Methods A total of 2083 patients with benign adnexal mass were treated by laparoscopy at Peking Union Medical College Hospital from January 2000 to December 2003. Their clinical data were reviewed retrospectively. All the adnexal masses suspicious of malignancy at the time of laparoscopy were sent for frozen section evaluation intraoperatively. The rates of unexpected intracystic vegetation and low malignant potential (LMP) tumor or malignancy were investigated. The sensitivity, specificity, positive predictive value, and negative predictive value of laparoscopic diagnosis for LMP or ovarian malignancies were calculated. The ratios were compared by Chi-square test and the continuous variables were tested using two-tailed t test. Results Of the 2083 patients, 16 had LMP or invasive tumors (0.77%), among which 14 were diagnosed histologically intraoperatively and 2 postoperatively. Fifty-five (2.6%) of the 2083 patients had unexpected intracystic vegetations. Their frozen sections showed benign tumors in 41 (74.5%), LMP tumors in 8 (14.5%), and focal invasive ovarian cancers (stage Ic) in 6 (10.9%). The final pathological diagnosis were benign tumors in 41 (74.5%), LMP tumors 7 (12.7%), and focal invasive ovarian cancers (stage Ic) in 7 (12.7%). Laparoscopy achieved a sensitivity of 87.5%, specificity of 98%, positive predictive value of 25.5%, and negative predictive value of 99.9% in the diagnosis of ovarian malignancies. 2067 cases with benign adnexal masses underwent laparoscopy successfully. No conversion to laparotomy, or intra- and postoperative complications in this series. Of the 16 patients with LMP or invasive ovarian cancer, seven underwent laparoscopic surgery including immediate staging laparoscopy in 3. The mean follow-up was 17.3 months for the 16 patients. Among them, 1 developed a recurrent LMP tumor in the contralateral ovary 36 months after laparoscopic salpingo-oophorectomy, and received subsequent laparoscopic cystectomy and pelvic lymph node sampling; the others had no evidence of recurrent tumor during the follow-up. Conclusion Laparoscopy is feasible for diagnosis of adnexal masses, and the surgery is safe for patients with benign ovarian tumors.