Many different techniques have been proposed to repair frontobasal dura mater lesions. Because of its low morbidity and high success rate, the endonasal approach has become a preferred route for treating cerebrospinal fluid fistulas of the anterior skull base. This article presents a retrospective evaluation of 136 endonasal duraplasties (126 patients) performed between July 1980 and May 1998 at a tertiary care facility. Follow-up consisted of clinical examinations including nasal endoscopy, objective measures, and telephone interviews. The following measures were used to evaluate the results of these duraplasties: postoperative nasal fluorescein endoscopy in 71 cases, computed tomographic cisternography in 2, nasal fluorescein endoscopy with computed tomographic cistemography in 19, magnetic resonance imaging in 6, and nasal fluorescein endoscopy with magnetic resonance imaging in 1. Tight closure was accomplished in 129 dural lesions (94.9%) on the first attempt. In 3 cases, recurrence of cerebrospinal fluid leakage was treated successfully by 1 endonasal revision, and in 1 case, a tight duraplasty was achieved after 2 endonasal revisions. Its high success rate, low rate of morbidity, and good long-term results recommend endonasal duraplasty as a primary treatment modality for frontobasal dural lesions. For extended frontobasal dural lesions, for which intracranial dural repair is the preferred approach, the endonasal approach should be used to close additional dural leaks of the sphenoid sinus.