To assess the safety of laparoscopic treatment of adnexal masses in the second trimester of pregnancy. Retrospective chart review (Canadian Task Force classification II-3. Large tertiary care medical center. Eleven women. Laparoscopic surgery. All masses were identified by ultrasound. The average gestational age at the time of surgery was 17 weeks, 4 days. In seven women the primary cannula was inserted in the left upper quadrant of the abdomen. Procedures were eight ovarian cystectomies, two oophorectomies, and one exploratory laparoscopy. Average operating time was 135 minutes (range 95-195 min). Average time exposed to carbon dioxide was 78 minutes (range 59-135 min). None of the masses was malignant. There were no fetal complications or malformations. No patients had preterm labor and all delivered at term. The increasing number of reported cases and our experience suggest that laparoscopic treatment of adnexal masses in the second trimester is safe and effective, but the surgeon must be skilled in advanced techniques of laparoscopic surgery.