PURPOSE: To compare the efficacy and safety of ofloxacin 0.3% ophthalmic solution with ciprofloxacin 0.3% ophthalmic solution in patients with culture-positive bacterial keratitis. METHODS: Patients with a microbiologic diagnosis of bacterial keratitis were included in this double-masked, parallel-group study and were randomized to treatment with either ofloxacin 0.3% or ciprofloxacin 0.3% ophthalmic solution. One drop of the study medication was instilled during the daytime according to the following schedule: every half-hour on study day 1, every hour on days 2 through 4, and every 2 hours on days 5 through 21. Healing, the primary outcome measure, was defined as complete reepithelialization, accompanied by nonprogression of stromal infiltrate for 2 days. Secondary outcome measures included signs and symptoms of infection. Patients were monitored throughout the study period for any adverse events. RESULTS: A total of 217 patients completed the study: 112 were treated with ofloxacin and 105 were treated with ciprofloxacin. Streptococcus pneumoniae was the most commonly encountered pathogen in all patients. Complete corneal reepithelialization occurred in 85% of those treated with ofloxacin and in 77% of those treated with ciprofloxacin (p = 0.32). The average time to corneal ulcer healing was 13.7 days in those treated with ofloxacin and 14.4 days in those treated with ciprofloxacin. Both treatments were well tolerated with no patient discontinuing the study because of side effects. CONCLUSION: Ofloxacin 0.3% and ciprofloxacin 0.3% ophthalmic solutions are effective and safe in the treatment of patients with culture-positive bacterial keratitis.