Objective: Maternal ovarian torsion in pregnancy is a rare complication. This study was conducted to review the clinical manifestations, and to compare the outcome between laparoscopy and laparotomy in women undergoing surgery for ovarian torsion (OT) during pregnancy. Materials and Methods: Using the International Classification of Disease, Ninth Revision, and Clinical Modification, we reviewed the clinical records of patients with OT during pregnancy between 1997 and 2008 at a university hospital. Results: Twenty pregnant women were identified with surgically proven OT, 10 in the first trimester, eight in the second, and two in the third. Thirteen (65%) cases were suspected before operation to be adnexal torsion. The most common symptom and sign were pelvic pain (95%) and an adnexal or pelvic mass (95%), followed by nausea and vomiting (65%), elevated white blood cell count >12×109/L (45%), and fever (10%). Most patients in the first trimester (75%) and a minority in the second and third trimesters (37.5%) received management via laparoscopy. Patients undergoing laparoscopy treatment had smaller ovarian masses and a shorter postoperative hospital stay than those receiving laparotomy. None of these patients had significant complications during or after surgery. However, the outcomes of pregnancy varied: 12 (60%) term deliveries, three (15%) preterm deliveries at over 31 gestational weeks, one missed abortion and four elective abortions in the first trimester. Conclusion: The diagnosis of OT during pregnancy is often missed due to nonspecific clinical features and uncommon objective findings. Detorsion only or detorsion plus ancillary procedures via laparoscopy is recommended to treat pregnant women suffering from OT, owing to the advantages of a shorter hospital stay and favorable surgical and pregnancy outcomes.