A corneal button obtained from a 58-year-old woman with Chandler's syndrome was studied by light and electron microscopy. Clinically, the patient had mild unilateral glaucoma, slight changes in the iris, endothelial dystrophy, and corneal edema that was increasingly sensitive to intraocular pressure. Corneal pathology included loss of large numbers of endothelial cells with consequent exposure of Descemet's membrane. Endothelial cells demonstrated irregular shape, partial loss of tight junctions, and increased numbers of cytoplasmic filaments. Some endothelial cells appeared metaplastic or perhaps were replaced by cells from some source other than the cornea. Proliferation of cells was not apparent. A thin layer of acellular tissue, containing long-spacing collagen and 15-nm-wide fibrils, was interposed between normal Descemet's membrane and the endothelium. These observations suggest a basis for the corneal edema that distinguishes Chandler's syndrome from other forms of essential iris atrophy.