Abstract Objective. To evaluate the long-term outcome and ovarian function in premenarchal and adolescent patients with malignant ovarian germ cell tumors after fertility-preserving surgery and adjuvant chemotherapy. Design. Retrospective review of medical records. Setting. Ajou University Hospital, a tertiary care hospital in South Korea. Population. Forty-five patients with malignant ovarian germ cell tumors. Methods. A retrospective analysis of patients with malignant ovarian germ cell tumors was conducted and a statistical analysis was performed. Main outcome measures. There were 9 premenarchal and 16 adolescent patients; the median ages at diagnosis were 7 and 18 years, respectively. All patients were treated with fertility-preserving surgery. Seventeen of the patients received adjuvant chemotherapy with bleomycin, etoposide, and cisplatin (68.0%). There were no disease recurrences or deaths. Of the nine premenarchal patients, eight (88.9%) subsequently had normal menarche. Among the 16 adolescent patients, 15 (93.8%) resumed normal menstruation and 1 had premature ovarian failure. Conclusion. Premenarchal and adolescent patients with malignant ovarian germ cell tumors have excellent survival with fertility-preserving surgery and adjuvant chemotherapy. The majority of these patients can have normal menarche and menstruation.