Calcifying epithelial odontogenic tumor (CEOT) is a rare benign neoplasm, with slow, localized, invasive, and asymptomatic growth. The involvement of the maxillary sinus by the neoplasm is rare, with its treatment controversial. The aim of this study was to describe the clinical, imaging, and therapeutic characteristics of a CEOT with maxillary sinus extension, as well as a literature review of therapeutic approaches and the prognoses obtained from cases of the same extension. In this case report, we report the case of a female patient, 49 years old, Caucasian, with mild asymmetry of the middle third of the face. Clinical and imaging examinations showed an intraosseous tumor in the posterior region of the left hemimaxillary, with imprecise limits and extension of 44×24×32 mm, compromising the alveolar process, maxillary posterior teeth, posterior hemipalatal region, left maxillary sinus, and orbital floor, associated with local expansion, tooth mobility, maxillary sinusopathy, and nasal obstruction. Calcifying epithelial odontogenic tumor diagnosis was obtained from incisional biopsy and histopathological examination. Surgical therapy of partial maxillectomy was performed from the Weber Ferguson Access with subsequent prosthetic rehabilitation. There were no postoperative complications. This case presented had satisfactory success with the therapy performed. The use of invasive therapies such as partial maxillectomies associated with transfacial approaches is an effective treatment for CEOT involving the maxillary sinus. Long-term follow-up is essential to avoid recurrences.