Purpose: To evaluate in vivo confocal microscopic features of the cornea in chronic and delayed mustard gas keratopathy (MGK). Design: Comparative cross-sectional study. Participants and Controls: Twenty-two eyes of 22 consecutive patients with MGK and 28 eyes of 28 normal unoperated subjects were enrolled. Methods: All subjects underwent corneal confocal scanning, and the findings were compared between the 2 groups. Main Outcome Measures: Qualitative (layer thickness measurement and cell count) and quantitative (nerve and deposit evaluation) findings of corneal confocal scanning. Results: All subjects with MGK and normal subjects were males, with no significant difference in mean age between the 2 groups. Mean central corneal thickness, mean epithelial thickness, mean cell density of basal epithelia, keratocyte density at 3 stromal layers, and endothelial cell density in the MGK group were significantly lower than those in the control group. Loss of keratocytes was predominantly observed in the anterior to middle stroma. In vivo confocal microscopy revealed lack of a subbasal nerve plexus, presence of intrastromal hyperreflective microdots, prominent thickened midstromal nerves, enlarged bizarre-looking keratocytes, amyloid degeneration, lipid keratopathy, posterior stromal folds, and endothelial cell pleomorphism and polymegathism. Conclusions: Corneal thinning, significant loss of keratocytes together with pleomorphic residual keratocytes, thickened midstromal nerve, stromal microdots, amyloid degeneration, and lipid keratopathy were remarkable findings observed in our cases. Although all the corneal layers were affected significantly by mustard gas, the anterior to middle parts of the cornea were more involved than the posterior parts.