Thirty-nine patients with advanced heavily pretreated epithelial carcinoma of the ovary were treated with mitoxantrone (dihydroxyanthracenedione hydrochloride). Twenty-five patients were started at a dose of 12 mg/m2 q 21d and 13 patients, with compromised bone marrow, at a dose of 10 mg/m2 q 21d. Two stable responses (6%) occurred in 31 fully evaluable patients. The median duration of survival was 17 weeks. The principal toxicity, hematopoietic (primarily leukopenia), was mild and well tolerated. We conclude that mitoxantrone is a relatively inactive drug in the treatment of epithelial ovarian carcinoma.