In the light of recent studies into lattice corneal dystrophies, with particular reference to gelsolin immunoreactivity, the authors set out to determine the ultrastructural localization of gelsolin molecules in lattice corneal dystrophy type I. Immunoelectron microscopy with a monoclonal antibody against the COOH-terminal of the native gelsolin molecule (clone GS-2C4) was used to compare antigelsolin reactivity in normal and dystrophic corneas. A gelsolin-like protein was observed at the level of the rough endoplasmic reticulum in both epithelial and endothelial cells, together with mild positive staining in stromal keratocytes of normal corneas; increased keratocytic immunoreactivity with positive staining within and/or around corneal amyloid deposits was revealed in dystrophic corneas. Observed intra- and extracellular immunoreactivity suggests that amyloid deposition may induce gelsolin synthesis; this actin-related protein could be involved in the rearrangement of corneal stroma in lattice corneal dystrophy.