Ciprofloxacin is a potent fluoroquinolone antibiotic with in vitro activity against many significant gram-positive and gram-negative ocular pathogens. A review of the experimental studies of this antibiotic shows bactericidal activity, a broad antimicrobial spectrum, and a low incidence of resistance. The growing body of experimental data supports the effectiveness of ciprofloxacin in the treatment of experimental keratitis and suggest that it be evaluated further in ocular infections.