The osteoplastic flap technique for treating frontal sinus mucoceles is described. This procedure has the advantages of: being a direct approach, which allows exposure of the entire sinus, provides complete obliteration of the sinus to prevent recurrence of the sinus disease, and prevents blind curettage of any exposed dura mater; leaving no facial deformity after the operation; being a relatively atraumatic procedure with low morbidity and minimum postoperative care; and allowing simultaneous surgery on both frontal sinuses when indicated.