Thirteen cases of primary ovarian seminoma have been referred to the Claudius Regaud Cancer Center during the last 2 decades, patients' ages ranging form 10 to 41 years with a peak in the 20's. Two patients were treated by surgery as definitive therapy, the others underwent combined radiation therapy (dose range 25 to 45 Gy) following surgical excision. The 2 patients treated by surgery alone had pelvic recurrences, whereas only 2 local failures appeared in the group treated by surgery and radiotherapy. Ten patients are asymptomatic and clinically free of disease after a mean follow-up of 3.5 years, the mean survival time of the series being 6 years. Because of the generally improved prognosis, surgical oophoropexy is recommended before radiotherapy.