Histopathological study of filamentary keratitis was done by using replica technique in five patients. The filaments are produced by sliding of the epithelial cells around small areas of focal degeneration of the superfical epithelium. In comparison to the filaments in other conditions, the filaments in KCS are smaller and thicker and do not show the torsional segment. The filaments contain degenerated epithelial cells and alcian blue-PAS positive mucoid material. Making a corneal replica may result in healing of filamentary keratitis.