Lipomas are the most commonly occurring soft tissue tumors, being intraosseous involvement very rare, and the jaw is its most uncommon bone location. Thus intraosseous mandibular lipomas constitute a real diagnostic challenge due to the unspecific clinical and radiographic features, therefore, only 28 cases have been reported in the literature. Herein we report an extremely rare case of an intraosseous mandibular lipoma that initially developed in Inferior alveolar nerve canal, characterize with dental cone beam computed tomography, and confirmed with histopathologic analysis after surgery. To the best of our knowledge, our case is one of the first cases of intraosseous mandibular lipomas involving the inferior alveolar nerve canal never been previously reported. Their rarity reinforces the need to document each and every case.