Ovarian carcinosarcoma, also called malignant mixed mesodermal tumour, is a rare ovarian tumour representing less than two per cent of ovarian cancers. Carcinosarcoma is an aggressive tumour, which associates some epithelial elements (carcinoma) with a stromal component (sarcoma). This tumour can be found in the female genital tractus, mostly in the uterus. It can be found even more rarely on the ovaries. The initial stage of the disease at the diagnostic is considered as the only prognostic factor. There is no existing consensus concerning treatment. Nevertheless, surgical treatment is paramount for the survival of patients. Response rates to chemotherapy are about 20%.