The malignant mixed Mesodermal (Mullerian) tumor (MMMT) is an uncommon tumor containing epithelial and mesenchymal components. MMMT of the ovary is rare, constituting less than 1% of all primary ovarian tumors. Most of all were heterologous type and 80% occur in postmenopausal women. It is a particularly aggressive and rapidly progressive tumor, especially in advanced stages. MMMT is highly malignant and the prognosis is poor due to frequent metastasis and recurrence. This disease is usually advanced when diagnosed, because it is asymptomatic in early stage. The survival rate is very low in spite of surgery, chemotherapy and radiotherapy. The optimal treatment for this neoplasm is still controversial because of its rarity. We experienced one case of malignant mixed mesodermal tumor of the ovary and report with brief review of literature.