Hepatic teratoma is an extremely rare tumour. Since 1898 only 28 cases of hepatic teratoma have been reported in the literature, including 21 in pediatrics. The diagnosis is often confirmed by the anatomopathological study and the therapeutic approach is multidisciplinary based essentially on surgery. We report the case of a 45-year-old woman with a history of ductal carcinoma of the right breast for which she underwent surgery. The patient presented with pain in the right hypochondrium, a diagnosis of hydatid cyst of the liver was made based on a cystic image of the right liver on ultrasound. It showed a heterogeneous thin-walled cystic image in the right liver suggesting a type IV hydatid cyst. The MRI was in favor of a fluid lesion of the hepatic dome evoking a remodeled hydatid cyst. During surgery, the liver was found of normal size and segment VIII is the seat of an oval formation 70/60 mm in diameter. A resection of the cystic formation with a closed cyst was performed. Histological analysis concluded with the diagnosis of mature teratoma with no signs of malignancy. After a follow-up of 12 years, the patient is in good health and without recurrence.