Background: The anatomy around the frontal sinus ostium exhibits a high degree of morphological variation. Nasal endoscopy and improved imaging techniques afford a more accurate assessment of frontal sinus disease. Methods: In the treatment of 102 nasal sides of 64 cases, we endonasally opened the ostium of frontal sinus in 101 nasal sides, by resection of anterior wall of agger nasi and anterior insertion of the middle turbinate at the agger nasi, without injury to normal mucosa of the frontal ostium area. Results: Postoperative follow-up results showed both freedom from or improvement of symptoms without necessity of revision surgery in about 89.2% of the cases. Conclusions: Endoscopic frontal sinus surgery appears to be a viable alternative for the treatment of frontal sinus disease. However, more cases and longer follow-up may be required before a definite conclusion can be reached.