Background: There have been only a few reports on the survival and management of patients with ovarian carcinosarcomas. We evaluated the clinical characteristics, outcomes and prognostic factors of ovarian carcinosarcomas. Methods: Retrospective analysis of data obtained from medical records of 40 patients treated at the Asan Medical Center, Seoul, Korea, between January 1989 and January 2008. Results: Median survival was significantly longer in patients <60 years of age than in those ≧60 (p = 0.001), patients with early-stage compared to advanced tumors (p = 0.035), those with optimally debulked tumors compared to suboptimally (p < 0.001) in the advanced stage, and patients treated with paclitaxel/platinum compared to patients treated with other chemotherapies (p < 0.001). The progression-free interval was longer in patients with early-stage (p = 0.003) and optimally debulked tumors (p = 0.001), as well as in those treated with paclitaxel/platinum (p = 0.049). Multivariate analysis showed that advanced-stage, non-optimal debulking and non-paclitaxel/platinum chemotherapy were significant independent predictors of a shorter progression-free interval, and that non-optimal debulking and non-paclitaxel/platinum chemotherapy were significant independent predictors of shorter overall survival. Conclusions: Early-stage optimal debulking and adequate chemotherapy can influence time to progression and survival, indicating that the most effective treatment for patients with ovarian carcinosarcomas consists of optimal debulking surgery followed by paclitaxel/platinum chemotherapy.