Twenty-four patients with pure dysgerminoma of the ovary were treated at The University of Iowa Hospitals and Clinics between 1935 and 1985. Ten patients had stage I unilateral tumors, and all are free of disease from 20-455 months (median, 100 months). All patients treated by unilateral adnexectomy alone for stage IA disease survived. Nine of 11 patients with advanced disease whose therapy began or was completed at our institution are alive without disease from 12-204 months (median, 60 months). Three patients were referred with recurrent disease, and none survived.