Whole-abdomen radiation therapy has been utilized as primary adjunctive therapy in the management of epithelial ovarian carcinomas with encouraging results. The results reported when using standard fractionation protocols in patients with recurrent or persistent ovarian carcinoma have been poor and treatment-related toxicities have been severe. There are reported theoretical and clinical advantages of hyperfractionation of ionizing radiation in treating malignancies. Fifteen patients have been treated with a twice-a-day whole-abdomen, open-field radiation technique delivering 80 cGy per fraction, to a total dose of 3040 cGy in 19 treatment days. All patients had Stage III epithelial ovarian carcinoma with persistent disease detected at pretreatment laparotomy after cis-platinum-based chemotherapy. All patients had moderately to poorly differentiated tumors with residual disease less than 1 cm. Acute side effects of treatment included mild to moderate nausea and diarrhea. Thrombocytopenia (less than 50,000) was noted in five patients. No bleeding or infectious complications were noted, and no patient required hospital admission for side effects. Disease recurred in nine patients with two still alive 13 and 52 months after starting irradiation. Six patients are currently alive without evidence of disease at follow-up, ranging from eight to 48 months. The mean survival to date is 20 months with four patients alive more than 2 years, and two patients alive for greater than 3 years from their radiation therapy. Patient tolerance has been acceptable, and both the short and long-term toxicities are minimal. Late side effects of treatment have not been noted. This technique offers a chance for a long, disease-free interval and possible cure in well-defined cases of chemotherapy-treated patients with persistent ovarian carcinoma.