Abstract: To evaluate the advantages and disadvantages of the electromagnetic image-guidance system in endoscopic sinus and skull base surgery. Methods: Of twelve patients, five had chronic sinusitis with or without nasal polyps, two cerebrospinal fluid rhinorrhea, one chronic sinusitis with cerebrospinal fluid rhinorrhea, one foreign body in the ethmoid sinus, one pituitary tumor, one invasive plexiform neurofibromatosis in frontal and ethmoid sinus and one Wegener granulomatosis in nasopharynx and clivus. All of them received endoscopic surgery with the Insta Trak image-guidance system. Result： All the patients were successfully operated on and no complications occurred. The preoperative preparation needed fifteen minutes on average. Conclusion： The electromagnetic imageguidance system could help surgeons identify critical anatomical structures and reduce surgical complications, especially in patients whose normal anatomic landmarks have been distorted by a prior surgery or disease process.

Key words: Tomography, X-ray, computed, Endoscopy, Nose diseases, Image-guidance system