In the case reported here, the authors observed ovarian small cell carcinoma of the pulmonary type as it developed. The patient was a 48-year-old woman who underwent a hysterectomy for CIN3 in 2007. A year later, the woman underwent screening for ovarian cancer. A gradually growing ovarian mass was noted. This mass was found to be a mixed tumor. This mixed tumor grew to 36 mm in size, and six months later it had enlarged to 119 mm. After surgery, the tumor was pathologically diagnosed as an ovarian small cell carcinoma of the pulmonary type with a neuroendocrine nature that was positive for CD56 and synaptophysin. Postoperatively, the patient received six courses of combined therapy with irinotecan and cisplatin (CPT-P therapy), and the patient has survived diseasefree for over two years. Findings suggested that ovarian small cell carcinoma of the pulmonary type is a type 1 ovarian malignancy that develops through an adenoma-carcinoma sequence.