Ciprofloxacin is a new quinolone antibiotic with a broad spectrum of activity against most aerobic gram-positive and gram-negative bacteria. Topical ciprofloxacin (3 mg/ml) was used to treat bacterial keratitis caused by methicillin-resistant strains of Staphylococcus aureus in two patients. Both corneal ulcers had been previously treated with other antibiotics without success. Topical ciprofloxacin was curative in both cases. The authors recommend the use of topical ciprofloxacin for methicillin-resistant S. aureus keratitis.