Maxillary sinus is the most frequent site of sinus aspergillosis. Infection of the ethmoid and frontal sinuses is uncommon and the sphenoid sinus is occasionally affected. Isolated aspergillosis of the sphenoid sinus is very rare. Sinus aspergillosis presents as several types: noo-invasive, invasive, fulminant and allergic. In October 1997, we experienced a 48-year-old female who suffered mild post-nasal drip and one episode of bloody whinorrhea. The patient had no systemic diseases or immunocompromised condition.CT scan of head showed normal sinuses except opacification in left sphenoid sinus, without any other abnormal findings in the nasopharyngeal area. She received medical treatment for six weeks, but the symptoms were not relieved. Endoscopic sphenoidotomy was performed and pathology revealed aspergillosis. The patient’s condition improved after surgery, and she has had no recurrence of disease after 6 months of follow up.