Aim : To evaluate the effect of surgically assisted rapid maxillary expansion on the nasal airway assissted by nasofibroscopy. Subjects and methods: Nine Patients were included in the present study. They were consecutive patients selected from the oral and maxillofacial surgery department that referred from orthodontic department Faculty of Dental Medicine, Al-Azhar University, Assuit branch in the period from September 2017 to October 2019 . They were adult patients of both sexes (3 males and 6 females). All patients were subjected to history taking , sinoscopic nasal examination. All patients had maxillary transverse deficiency associated primarily with functional impairments, such as posterior uni- or bilateral cross bite, dental crowding, reduced nasal respiratory function or anterior-posterior skeletal anomalies and they were indicated for surgically assisted rapid maxillary expansion. Preoperative intracanine and intramolar distances (C1, C2, M1, M2 ) was measured by digital caliper on Study cast. Measuring area of both nasal cavities by nasofibroscopy were done in ENT department of Al Azhar university hospital, Assuit. The operation was conducted under general anesthesia. After surgery, clinical evaluations ware done at intervals of 2, 4, 7 and 15 days and then all data obtained from nasofibroscopy by pixels and transformed by typography program in to millimeters. Result: Results of the current study have indicated that nasofibroscopy showed that was improvement in nasal obstruction after maxillary expansion. Conclusion: Surgically assisted rapid maxillary expansion is an effective method of widening the nasal passages and reducing nasal resistance that assisted by nasofibroscopy.