The effect of concentrated antibiotics on the healing rate of epithelial erosions in rabbit was measured by serial standardized photography. Histological studies were also performed. Our results suggest that Kanamycin 30 mg/ml (p less than 0.001), Penicillin 100,000 units/ml (p less than 0.001) and Vancomycin 31 mg/ml (p less than 0.01) administered six times a day retard the epithelial wound healing compared with control animals which received isotonic NaCl.