Malignant mixed mesodermal tumor (MMMT) of the ovary is very rare, constituting 1% of all primary ovarian tumors. MMMT is a highly aggressive and rapidly progressive tumor with a poor long-term prognosis. Though aggressive surgery is generally felt to be indicated for this tumor, there is no uniform opinion about adjuvant therapy. We have experienced a case of primary malignant mixed mesodermal tumor of the ovary and report it with a brief review of literatures.