Serous cystadenofibroma of the ovary is a cystic neoplasm containing fibrous component, and lining of high, cylindrical, and ciliated epithelial cells surrounded by clear serous fluid, with smooth or papillary surface and abundant vessels. Serous cystadenofibroma in the present case report was an incidental discovery observed during an abdominal and pelvic cavity review performed in a 39-week elective cesarean section applied to in a 32-year-old patient who presented uneventful pregnancy. The importance of conducting inventories of these cavities during cesarean sections to identify asymptomatic adnexal masses unseen in prenatal ultrasonography is clear.