In this study we treated 19 patients with relapsed ovarian cancer with malignant peritoneal effusion. All patients were previously treated with cisplatin-containing regimens. Intraperitoneal mitoxantrone was administered at a dosage of 20-30 mg/mq repeated every 28 days if ascites was still present. No patient was treated with systemic chemotherapy during the study. In 15 of 19 patients progressive ascites reduction was obtained. Moreover, in 4 of 15 responsive patients, a progressive reduction of the quantity of ascites was observed even though the abdominal masses demonstrated an increase in volume. Serum concentrations of Mitoxantrone (MXN) were determined, in ten patients, by high performance liquid chromatography with spectrophotometric detection, and low serum levels (1-30 ng/ml) with a maximum at the first or second hour were revealed. In conclusion, in patients with ovarian carcinoma and recurrent neoplastic ascites, palliative treatment with mitoxantrone was effective and well tolerated. The reduction of ascites and frequency of paracentesis represents a marked advantage for these patients and improves their quality of life.