Primary small cell carcinoma of the ovary is an extremely rare and highly malignant ovarian malignancy. The tissue origin of this type of cancer is still unclear, and it is characterized by rapid progression and a discouraging prognosis. The clinical presentation of small cell carcinoma of the ovary lacks specificity, and there are currently no effective treatment options available. Therefore, it is crucial to improve the understanding and identification of this disease. In this paper, we present a case of composite small cell carcinoma of the ovary with mucinous adenocarcinoma and provide a comprehensive review of the relevant literature.