Twenty-five cases of pure ovarian dysgerminoma treated at UCLA Medical Center between 1958 and 1992 were reviewed retrospectively. Patterns of recurrence and overall survival were analyzed with regard to primary surgery (conservative versus nonconservative), use of adjuvant therapy, and stage of disease. Fourteen patients (56%) underwent conservative surgical therapy defined as preservation of the contralateral ovary, 10 patients (40%) had nonconservative primary surgery, and one patient (4%) had chemotherapy as primary treatment. Three patients (12%) received adjuvant chemotherapy and nine patients (36%) received postoperative radiation therapy. Fifteen patients (60%) had stage I disease, four (16%) stage II, and three each (12%) had stage III and IV disease. Nine patients (36%) experienced recurrence of disease. Seven of these nine patients (78%) had stage I disease and all seven had undergone conservative primary surgery with preservation of the contralateral ovary. Six of the seven had received no adjuvant therapy. Only one of these seven patients experienced recurrence in the preserved ovary. She was found to have a dysgenetic ovary and an XY karyotype. Three patients with recurrent disease had received radiation therapy after primary surgery. Twenty patients (80%) were alive without disease at follow-up, two patients (8%) were alive with disease, and three (12%) had died of disease. There was no statistically significant difference in recurrence rates between those patients treated with conservative surgery and those treated with nonconservative surgery, although the total number of patients with recurrences was greater in the former group. Our data suggest that a conservative surgical approach is the preferred treatment in patients with pure dysgerminoma of the ovary who desire future fertility. Lack of adjuvant chemotherapy or radiation therapy, rather than type of initial surgery, may be associated with a higher risk of recurrence.