Malignant mixed mesodermal tumor (MMMT) of the ovary is a rare, but usually fatal, cancer for which there exists no proven postsurgical therapy. The Gynecologic Oncology Group has evaluated adriamycin in this disease at a dose of 75/m2. Among 10 evaluable cases with measurable disease there was one partial response and no complete responses. Of 21 cases with nonmeasurable tumor four remain clinically free of cancer from 2 to 45 months. There were two treatment-related deaths. We conclude that adriamycin alone as first-line chemotherapy in patients with MMMT of the ovary is not sufficiently active to be clinically useful.