Ovarian epithelial tumors of nongerm cell origin with true choriocarcinomatous differentiation are rare. To date, there are only 5 documented cases in the literature. In the reported cases, the epithelial component was of mixed cell types or of mucinous differentiation. To the best of our knowledge, an ovarian carcinoma exclusively of clear cell differentiation coexisting with a pure choriocarcinoma has not been reported earlier. A 48-year-old postmenopausal woman was found to have a large pelvic mass with lung and liver metastases. Trucut biopsy of the mass showed a poorly differentiated carcinoma that was immunoreactive for CK7 and hCG. She received 6 cycles of neoadjuvant chemotherapy that included 3 cycles of etoposide/cisplatin and 3 cycles of paclitaxel/etoposide-paclitaxel/carboplatin (TE/TP) with partial response. Debulking surgery was carried out subsequently. Pathologic examination showed an ovarian clear cell carcinoma with a second component of choriocarcinoma in which the bilaminar growth pattern of cytotrophoblast and syncytiotrophoblasts was striking. Despite additional therapy, which included 2 cycles of TE/TP and 2 cycles of gemcitabine/taxotere, the disease progressed and the patient died 11 months postoperatively. This report showed that ovarian clear cell carcinoma with choriocarcinomatous differentiation is a highly aggressive tumor and has a very poor prognosis. Nonetheless, there may be a role for neoadjuvant chemotherapy that targets both the clear cell and the choriocarcinoma components to reduce the volume of the disease before debulking surgery.