Frontal sinus mucocele usually presents with frontal headache and frequently with proptosis as well as diplopia. These cases over the years have required either conservative or radical surgical procedure. However, recently functional endoscopic sinus surgery affords the potential to decrease the operative morbidty of surgery by direct endoscopic visualization under local anesthesia. Besides, it makes it possible of solve the problems of visualizing the operative area after surgery, and relieves the difficulty of imaging the sinus radiographically after an obliterative procedure. We have experienced a case of frontal sinus mucocele which was satisfactory treated under endoscopic approach. Follwing surgery, no disease recurrence has been noted to data with endoscopic and radiologic follow-up of up to 7 months. The etiology, presenting features, and treatment of this mucocele were reviwed.