A study was conducted to determine the safety and efficacy of topically applied ciprofloxacin ophthalmic solution in a pediatric population experiencing acute bacterial conjunctivitis. Topically applied ciprofloxacin (3 mg/mL) is known to be a safe and effective treatment for adults suffering from bacterial conjunctivitis; however, the safety and effectiveness of this broad-spectrum fluoroquinolone in pediatric patients is not well established. Ciprofloxacin was evaluated in a double-blind, randomized, controlled study of 257 patients ranging from 0 (i.e., less than 1 year) to 12 years of age from 33 geographically diverse medical centers. The children received either 0.3% ciprofloxacin ophthalmic solution (Ciloxan, Alcon Laboratories, Fort Worth, TX) or tobramycin ophthalmic solution (Tobrex, Alcon Laboratories, Fort Worth, TX). Both test medications were administered topically every 2 hours on days 1 and 2 followed by every 4 hours on days 3 through 7. Eyes were cultured prior to enrollment and again on day 7. Treatment efficacy as determined by microbiological culture data and physicians' judgment of overall resolution was similar for the ciprofloxacin and tobramycin groups. Microbiological eradication was observed in 90.1% of the ciprofloxacin group and 84.3% of the tobramycin group (P = 0.29). Physicians judged 87.0% of the ciprofloxacin patients and 89.9% of the tobramycin patients clinically cured on day 7 (P > 0.5). There were no serious adverse medical events attributable to either treatment. This study showed that topically applied ciprofloxacin ophthalmic solution is safe and effective in a pediatric population experiencing acute bacterial conjunctivitis.