Corneal epithelium antibodies were detected in patients with corneal melting disease (55%), uveitis (42%), corneal transplantation (42%) and marginal furrow disease (20%). These antibodies were not found in herpetic keratitis patients. In control groups, consisting of ocular surgery patients (glaucoma, retinal detachment and cataract) and persons without a history of ocular disease, approximately 4% of the subjects had these antibodies. To investigate the possible role of trauma to the cornea as an initiator of corneal epithelium antibodies, these antibodies were determined in rabbits after alkaline burns were made on the cornea. These antibodies were detected one week later and disappeared after six weeks. Serum from three patients with corneal melting disease and corneal transplantation containing a high antibody titre against corneal epithelium were used to isolate corneal epithelium antigens. A 54 kD and a 17 kD corneal epithelium antigen were isolated. The incidence of autoantibodies directed against these antigens was investigated in patients with corneal melting disease, uveitis and corneal transplantation using an ELISA. 50% of the sera positive in the immunofluorescence test were positive in the ELISA.