Only 2.9% of head and neck schwannomas are found in the nasal cavity or paranasal sinuses. A 47-year-old man preseted with a complaint of left nasal obstruction, rhinorrhea, epiphora and left facial pain. At first, a malignant tumor was suspected, because computed tomography showed a large mass and bony destruction of the left maxillary sinus.It was difficult to make the diagnosis of schwannoma. On biopsy, the intraoperative findings was non-malignant tumor (schwannoma or neurofibroma). Then, complete endscopic excision of the tumor was performed by the Caldwell-Luc method. It is important to resect widely as soon as possible because of the possibility of malignancy.