Ovarian pulmonary-type small cell carcinoma is a rare and extremely aggressive neoplasm. We report the occurrence of an ovarian small cell carcinoma of pulmonary type in a 54-year-old woman. She underwent a total abdominal hysterectomy with a bilateral salpingo-oophorectomy and infracolic omentectomy. A diagnosis of stage IIIA pulmonary-type small cell carcinoma was rendered. The tumor appeared to be composed of a solid growth of small cells arranged in sheets and closely packed nests with insular arrangements separated by a fibrous stroma. The tumor cells had hyperchromatic nuclei with inconspicuous nucleoli and scanty cytoplasm. Rosette and rosette-like structures were scattered. Immunohistochemical staining showed positivity for synaptophysin, neural cell adhesion molecule (NCAM), and focally for chromogranin. Cytokeratin and neuron-specific enolase (NSE) were also positive. Over 80% of the tumor cells showed strong reactivity for MIB-1. Electron microscopy showed neuroendocrine granules. She was effectively treated with paclitaxel plus carboplatin after the surgery.