Abstract: Ovarian cystic adenofibroma is a rare ovarian tumor of epithelial origin and is composed of Mullerian epithelium and fibrostromal cells on the surface of the ovary. Its clinical incidence is rare, and serous is the most common. This article reports a case of mucinous cystic fibroadenoma in a 76-year-old female who presented abdominal pain for more than two years and a palpable mass in the lower abdomen for eight months. MRI resonance imaging revealed lesions of varying sizes, an uneven signal in the cystic cavity, and significantly low signal changes in the solid components on T2WI. Imaging diagnosis of cystic adenofibroma is performed. The post-operative pathological result of the patient indicates mucinous cystic fibroadenoma, and the post-operative follow-up is favorable. This article aims to provide an imaging description and summary of the disease to improve its diagnosis accuracy.