Several studies during the last 15 years have elucidated the role of postoperative external beam radiation therapy as curative management of some subsets of patients with ovarian cancer. Despite this, the use of radiation therapy in patients with ovarian cancer has remained a controversial subject. Substantially improved cure rates have not been realized during the past decade despite the early promise of high response rates to cisplatin chemotherapy. Thus, it is important that all currently effective therapies be used for maximum therapeutic gain. This article will review the evidence that radiation therapy is curative in ovarian cancer and highlight the criteria, including stage and grade of disease and tumor residuum, by which patients suitable for such therapy are selected. The rationale for the use of whole abdominopelvic irradiation rather than pelvic or lower abdominal treatment will be discussed, as will the optimal radiation technique and its attendant morbidity. Limited data pertinent to the controversy over the use of radiation therapy versus chemotherapy in early disease, will be reviewed. The possible benefits of consolidation abdominopelvic radiation therapy after chemotherapy in highly selected patients with well-differentiated microscopic residual disease at second-look laparotomy or with no residual disease but high a risk for relapse will be considered.