Malignant fibrous histiocytoma (MFH) is the most common soft-tissue sarcoma of late adult life occurring predominantly in the extremities and the retroperitoneum. MFH of the ovary is very rare, with only six cases previously reported. A 67-year-old woman with a right pelvic tumor highly suspicious of ovarian carcinoma was submitted to exploratory laparotomy. Total abdominal hysterectomy, bilateral salpingo-oophorectomy, total omentectomy, pelvic and paraaortic lymphadenectomy with right hemicolectomy along with permanent cutaneous ileostomy were performed. Since a storiform-pleomorphic type of MHF was diagnosed from histopathological and immunohistochemical findings, chemotherapy was proposed as the postoperative treatment. Despite extensive surgery with negative surgical margins, the patient had recurrence of the tumor within four months, and was submitted to secondary surgery. A combination of chemo- and radiotherapy was performed postoperatively, but the patient developed respiratory problems and died one year later from the primary diagnosis.