Optic neuropathy, an uncommon manifestation occurs in 5% of patients with Graves' ophthalmopathy. Its outcome is good if early and proper treatment given. We reported a 49 years old male patient of Graves' disease with bilateral optic neuropathy. He underwent bilateral transnasal endoscopic orbital decompression with marked improvement of visual acuity bilaterally. The preoperative visual acuity was 6/36 in his right eye and 6/60 in his left eye. Two days after operation, his visual acuity was 6/12 in his right eye and 6/24 in his left eye. Transnasal endoscopic orbital decompression is a choice of treatment in optic neuropathy in thyroid ophthalmopathy after trial of corticosteroids.