Paranasal sinus aspergillosis has usually been considered a rare disease, but it is seen more frequently in both immunocompromised and immunocompetent persons. Invasion may reach the sinuses via the nose or from the mouth after dental procedures. Even though the infection is usually limited to one or more sinuses, it may in certain cases extend to vascular or intracranial structures with a fatal outcome. In these cases, aggressive treatment is justified. We report a case of maxillary sinus aspergillosis that developed after dental extraction. Attention should be given to this possibility even after an apparently uncomplicated dental extraction.