A 43-year-old woman developed right frontal headache and decreased vision in her OD 14 months after treatment of an intracranial aneurysm by wrapping with cotton gauze. A junctional visual field defect was present, and an MRI revealed a contrast-enhancing mass involving the right optic nerve, lateral chiasm, optic tract, and cavernous sinus. Biopsy demonstrated a marked inflammatory reaction mixed with strands of birefringent cotton gauze. Despite treatment with high-dose corticosteroids, visual loss progressed to bilateral blindness. This is the 30th reported case of an intracranial inflammatory tumor developing from a gauze-wrapped aneurysm ("gauzoma" or "muslinoma") and the worst reported visual outcome. Most cases have occurred in women and involved the optic nerves or chiasm. Visual improvement has sometimes occurred after treatment with abscess drainage, debulking, and/or corticosteroids. A rare complication of aneurysm wrapping, gauzomas causing visual loss have been reported up to 54 months after surgery.