Copyright © 2022 by Mutaz B. Habal, MD.Intraosseous mucoepidermoid carcinoma (IMEC) is a rare neoplasm of the jawbones. Although hypotheses focused on the malignant transformation of the epithelial mucosa of odontogenic cysts or ectopic salivary gland tissue have been suggested, the etiology of the disease is still unclear. It is more frequent in middle-aged individuals, has a slight female predilection, and is more common in the mandible than in the maxilla. Cortical enlargement is the most common symptom, while some lesions are detected by coincidence on radiography. This paper reports an IMEC of the mandible of a 35-year-old female, possibly arising from the remains of an odontogenic cyst associated with an unerupted mandibular molar, which was operated in an external center 5 years ago before IMEC diagnosis.