We present a 50-year-old woman with agenesis of the sphenoid sinuses. She was referred for evaluation of the aeration status of the sphenoid sinus and related nasal structures before endoscopic transsphenoidal hypophysectomy for pituitary microadenoma. Axial and coronal computed tomography (CT) scans revealed absence of the sphenoid sinuses and the right posterior ethmoidal cell. Agenesis of sphenoid sinuses documented using CT scans is uncommon. One case with a history of Hand-Schuller-Christian disease has been reported in the English language literature. In the case reported here agenesis of the sphenoid sinuses was not accompanied by craniofacial anomaly or skeletal disease.