From July, 1989 to June, 1998 forty-two patients with malignant germ cell tumors of the ovary treated in the department of Obstetrics and Gynecology, University of Ulsan, Asan Medical Center, were identified. Demographic characteristics, symptoms, signs, stage, tumor grade, mode of therapy and results of follow-up of those patients were reviewed retrospectively. The patients with malignant germ cell tumor constituted 11.1% of all ovarian malignancies and 5.6% of all ovarian germ cell tumors ecountered during this period. The most common histologic subtype was dysgerminoma (26.2%) followed by endodermal sinus tumor (23.8%) and immature teratoma (19.0%). The age of the patients ranged from 8 to 64 years (mean+/-S.D.; 26.0+/-12.9) and the mean parity was 0.8 (+/-1.6). The most frequent initial symptoms were adbominal pain (33.3%) or abdominal distension (31.0%). Most had stage I(25 cases, 59.9%) or II(6 cases, 14.3%) diseases. Elevated level of serum alpha-FP was observed in all cases of endodermal sinus tumor and embryonal cell carcinoma, CA 125 was elevated in 63.9% of all malignant germ cell tumors. Thirty-one patients (73.8%) were treated by surgery and chemotherapy and 10 patients (23.8%) by surgery only. The major chemotherapeutic regimens were BEP (bleomycin +etoposide +cisplatin) and VAC (vincristine +actinomycin-D +cytoxan). The mean follow-up duration was 24.6 (+/-23.5) months and 2-year survival rate was 88.6% (+/-0.6).