Masses originating from the abdominal/pelvic organs can rarely grow into or be found outside the abdominal cavity. The majority of ovarian tumors are usually located around the uterus, but several reports have described about ovarian tumors occurring with an abdominal hernia. However, there is no report describing the MRI findings of a malignant ovarian tumor presenting as a ventral hernia. We present a case of a mucinous ovarian carcinoma that manifested as a spontaneous ventral herniation of the cystic component, and we also present the ultrasonography and MRI findings.