We conducted a clinical and pathologic review of nine patients with immature ovarian teratoma. The histologic grade of the tumor seemed to be a reliable indicator of prognosis. Low stage and low grade immature ovarian teratomas have an excellent prognosis. Platinum-based chemotherapy has been confirmed to be effective in the management of patients with ovarian germ cell tumors. Low grade pure ovarian immature teratoma is a potentially curable disease and a fertility-sparing surgical approach is possible.