The efficacy and safety of ciprofloxacin (0.3%) ophthalmic solution and rifamycin (1%) ophthalmic solution for the treatment of bacterial conjunctivitis and blepharitis was compared in this randomized, double-masked, parallel-group study. Forty-one patients, 19 on ciprofloxacin and 22 on rifamycin, were culture-positive on admission and evaluated for efficacy. There was clinical improvement in more than 90% of patients in each group at the end of the seven-day treatment period. However, clinical cure rates on day 7 appeared to be higher with ciprofloxacin (53%) than rifamycin (23%; p = 0.061, Mann-Whitney test). Bacteriological eradication rates were comparable: the infecting organisms were eradicated in 68% of patients on ciprofloxacin and 77% with rifamycin. There were no serious adverse reactions to either treatment. One patient in each group was withdrawn on account of a mild allergy. In conclusion, topical ciprofloxacin was effective and well tolerated and would be a particularly useful agent for the treatment of bacterial conjunctivitis and blepharitis.