A 49-year-old female presented with a low abdominal tumor. Before operation, she had neither evidence of androgen excess nor abnormal tumor marker values, but US, CT and MRI findings strongly suggested the possibility of a malignant ovarian tumor. Her operative findings were as follows: a goose egg-sized main tumor in the low abdomen, with a walnut-sized tumor in the right side, which grew around the right ureter, causing right non-functional kidney. Pathological examination revealed her tumor was a very rare type of malignant Sertoli-Leidig cell tumor with pelvic lymph nodes metastases. Most patients with this disease usually have good prognoses, but with metastasis or recurrence, no therapy is as effective as in epithelial ovarian cancer. In this case, we selected a new combination chemotherapy of CBDCA, Etoposide and Epirubicin, considering current changes in the chemotherapy for ovarian germ cell tumors and Sertoli-Leidig cell tumors of testis. Now, 1 year and 4 months after operation, she has no evidence of recurrence or metastasis. This study proposes a new, presumably more effective chemotherapy for an ovarian malignant Sertoli-Leidig cell tumor.