Sertoli-Leydig cell tumors are a group of tumors composed of variable proportions of Sertoli cells, Leydig cells, and sometimes heterologous elements. We describe the case of a 68-yr-old woman who presented with abdominal distention. A computed tomographic scan revealed a large right adnexal mass without evidence of intrahepatic tumors, and a complete cytoreductive surgery was performed. Pathologic examination revealed a moderately differentiated Sertoli-Leydig cell tumor with various heterologous elements, including gastrointestinal-type glands, insular carcinoid, and aggregations of hepatocytes without significant cytologic atypia. Moreover, adjacent to these hepatocytes, extensive overgrowth of highly atypical hepatocyte-like cells, providing a striking morphologic similarity to hepatocellular carcinoma of the liver, was identified. Both the heterologous hepatocytes and hepatocellular carcinomatous tumor cells were immunohistochemically positive for alpha-fetoprotein, hepatocyte paraffin 1, and arginase-1. Some Sertoli cells adjacent to the heterologous hepatocytes were also positive for alpha-fetoprotein and hepatocyte paraffin 1. The present case showed that a tumor morphologically and immunohistochemically analogous to hepatocellular carcinoma of the liver can arise in the ovary, in association with Sertoli-Leydig cell tumors.