Aspergillosis of the maxillary sinus is rarely seen in nonimmunocompromised patients. Among paranasal sinus infections associated with aspergillosis, the most common subtype is Aspergillus fumigatus. A 41-year-old woman presented with facial pain. She had a five-year history of root canal filling in the right upper molar teeth. Paranasal sinus tomography showed fungal sinusitis of radiopaque appearance, giving the impression of a foreign body in the maxillary sinus. The patient underwent endoscopic sinus surgery to purge infection of the maxillary sinus. Pathological examination revealed aspergillosis of the maxillary sinus.