Introduction: The odontogenic myxoma is a tumor of the jaws which arises from the mesenchymal portion of the tooth germ, either the dental papilla, the follicle, or the periodontal ligament. It is a slow-growing, painless, nonmetastasizing, central tumor of the jaws, chiefly the mandible. Radiographically, the classic presentation may vary from a unilocular radiolucency to a multilocular lesion with well-defined or diffuse margins. On histological study, it is composed of triangular or stellate connective cells, anastomosed by fine extensions, and embedded in abundant mucoid material. Case presentation: We present the unusual case of an odontogenic myxoma involving a 37-year-old female patient, which had acquired large dimensions and involved the right half of the mandible, including the ramus; the patient was treated with large resection surgery, with satisfying medium-term results. Clinical discussion: Early diagnosis of such lesions is very important, as the patient avoids extensive surgical procedures that involve losing a large part of the jawbones and their subsequent impact on the patient’s quality of life. Conclusion: Although there is no fixed treatment plan for the management of odontogenic myxoma, treatment includes surgical management that may range from simple enucleation and curettage to surgical excision; wide surgical resection is appropriate for cases of large size to avoid recurrence.