BACKGROUND To determine the most important prognostic factors in patients with malignant germ cell tumors of the ovary. METHODS Age, histologic type, tumor size, stage, treatment mode, type of surgery of 67 patients with malignant germ cell tumors managed consecutively were evaluated retrospectively using multivariate analysis. RESULTS The overall survival rate was 60.6%. This figure was 78.5% for dysgerminoma, 53.3% for immature teratoma, 12.0% for endodermal sinus tumor, 33.3% for mixed germ cell tumor and 100.0% for others. The patients with endodermal sinus tumor had significantly poorer survival than other groups. Among the factors analyzed for survival histologic type was found to be the most significant predictor for survival. CONCLUSIONS Finding of histologic type as the strongest independent risk factor may be evaluated in correlation with the literature that these tumors have historically been investigated as dysgerminomatous and nondysgerminomatous tumors. Furthermore, endodermal sinus tumors had long been known for poor survival. Based on this data, despite advent of staging and effective chemotherapy, prognosis still is basically related to histologic type and histology of tumor should be taken into account while comparing results.