Esthesioneuroblastoma is a rare malignant tumor arising from olfactory epithelium. The clinical course of this tumor is charaterized by local destruction with aggressiveness, frequent local recurrence and not uncommonly distant metastasis and cervical nodal metastasis. Therefore the treatment recommended is combined therapy of surgery and radiation. We have experienced three advanced cases of esthesioneuroblastoma in the nasal cavity extending into the frontal sinus, ethmoidal sinus, and skull base. Therfore, we report these cases.