Female adnexal tumors of probable Wolffian origin (FATWOs) are extremely rare tumors, with only around 100 cases published worldwide. FATWOs are most frequently found in the broad ligament, but these can also appear in the mesosalpinx, Fallopian tube, ovary, paravaginal region or peritoneum. We present a case of a 68-year-old female with a history of painless abdominal distension and frequent urination, with palpable big abdominal mass. Initial diagnosis was made using ultrasound and computed tomography scan that showed 22 × 21-cm tumor with solid and cystic components. Blood test showed elevated serum levels of CA 125, HE4 and Roma index. Intraoperatively, a large abdominopelvic encapsulated mass, fixated to surrounding tissue, was found. Our patient underwent hysterectomy 12 years ago. Total tumor resection, including bilateral adnexectomy, was performed. At 6 months of following, there was no evidence of disease. Here, we report extremely rare abdominal tumors and one of the biggest FATWOs reported so far.