The ophthalmological changes in two patients with Erdheim-Chester disease are described. These consist of exophthalmos, ophthalmoplegia, xanthelasma, optic disc swelling, blindness due to optic atrophy, retinal striae, and bilateral enhancing orbital masses on CT scan. The clinical and histopathologic findings of Erdheim-Chester disease are reviewed and the manifestations in two patients with orbital change are presented. This is believed to be the first report describing the ophthalmological manifestations of Erdheim-Chester disease. Our observations support the view that Erdheim-Chester disease is unrelated to the histiocytosis X group.