The aim of this study was to summarize our experience of ovarian cancer diagnosed during pregnancy, to review the literature concerned, and to discuss the rationale for therapy. Twenty-two patients of ovarian malignancies complicating pregnancy were treated at Peking Union Medical College Hospital between 1985 and 2003. Data on treatment and follow-up were reviewed, and their outcomes were analyzed by survival analysis. The incidence of ovarian carcinoma complicating pregnancy in the series was 0.073/1000 pregnancies. Nine (40.9%) were found with ovarian malignant germ cell tumors, six (27.3%) with low malignant potential tumors, five (22.7%) with invasive epithelial tumors, and two (9.1%) with sex cord stromal tumors. Sixteen (72.7%) of the patients were diagnosed in stage I and had achieved complete remission. Four of the five in advanced stage died. Ascites presenting at diagnosis implies advanced disease and gloomy prognosis. The mean follow-up was 47.8 months. The prognosis was significantly related with stage and histologic type (P < 0.05). Thirteen healthy live babies were recorded in this group, and one premature newborn died of respiratory distress syndrome. The clinical characters and prognosis of ovarian cancers complicating pregnancy are similar to those of nonpregnant, reproductive-age women. Management depends on histology of the tumor, stage of the tumor, and the term of the pregnancy. In most of cases, conservative surgical treatment could be performed with adequate staging and debulking equal to the treatment of nonpregnant women. Chemotherapy is not contraindicated during the second or third trimester, but the choice of couple must be considered.