A case of gonadoblastoma with dysgerminoma and choriocarcinoma in the right ovary of a 23-year-old woman is reported. A case of gonadoblastoma without a Y chromosome is very rare. She had a 46XX chromosomes, normal genitalia, no history of menstrual irregularities, thereby differing from the other reproted case. The patient had a normal term pregnancy 2 years after surgery and chemotherapy. It is suggested that gonadoblastoma may occur in functionally and morphologically normal gonads. There have been no signs of recurrence or metastasis for 3 years after the first operation.