A 10-year-old boy developed loss of central vision in both eyes due to compression of the optic nerves by a mass arising from the sphenoid and ethmoid sinuses. Histopathologic examination of biopsy specimens showed a fibrous matrix composed of spindle-shaped cells interspersed with small and large channels, characteristic of an aneurysmal bons cyst. One year after partial excision of the intracranial and extracranial portions fo the lesions, vision had returned to nearly normal levels. Aneurysmal bone cysts rarely involve the orbits or other cranial bones to produce ocular signs and symptoms. However, since this lesion probably represents reactive proliferation of bony tissues, rather than neoplasia, the prognosis for vision and life is good.