Agenesis of paranasal sinuses is an uncommon finding mainly seen in the frontal and maxillary sinuses. Agenesis of sphenoid sinuses is an extremely rare condition. In this article, we present an 18-year-old female patient suffering from headache and nasal obstruction without any skeletal or cranial anomalies. Axial, coronal and sagittal computed tomography revealed absent sphenoid sinuses. Surgeons should be aware of sphenoid sinus agenesis, when transsphenoidal hypophysectomy and endoscopic sinus surgery are scheduled, in particular.