Exophthalmos from Graves' disease can result in visual disability and cosmetic deformity. Surgical treatment of this disorder is now possible through an intranasal endoscopic approach that allows removal of the medial orbital wall and floor without an external incision. Endoscopic orbital decompression was performed on 22 orbits in 14 patients for treatment of progressive exophthalmos. Local anesthesia was used in five cases. Sixteen procedures involved a concurrent lateral orbital decompression performed through an external approach. There were no intraoperative or postoperative complications. Visual acuity remained stable or improved in all cases. Proptosis was reduced an average of 3.2 +/- 1.1 mm (range 2 to 4.5 mm) by endoscopic decompression alone. When a lateral decompression was also performed, proptosis was reduced by an additional 2.4 mm, for an average improvement of 5.6 +/- 1.7 mm (range 2 to 8 mm). Endoscopic orbital decompression appears to be a safe technique for the treatment of exophthalmos that can be performed effectively with the patient under general or local anesthesia.