Ameloblastic carcinoma is a rare, malignant epithelial odontogenic tumor with a poor prognosis. Histopathologically it preserves an ameloblastomatous differentiation pattern but shows cytological features of malignancy. Due to its rarity, there is limited information on its biological behavior, which is recognized in the literature for being nonspecific and variable, as it may present as a lesion with characteristics compatible with a benign lesion or as a highly malignant aggressive pathological entity. The latter has been a difficulty not only in its diagnosis but also in the therapeutical planning. This article reports a case of a mandibular ameloblastic carcinoma occurring in a patient in the seventh decade of life, highlighting its variable clinical, imaging and histological characteristics that allowed us to reach a definitive diagnosis.