Otic drops of either ciprofloxacin 0.2% solution (CIP) or a combination of polymyxin B, neomycin, and hydrocortisone suspension (PNH) were administered for 6 to 12 days to patients (14-71 years old) with chronic suppurative otitis media in a randomized, nonblinded, multicenter clinical trial. Two hundred thirty-two enrolled patients were analyzed for efficacy on a "per protocol" basis. The most frequently identified causal agents were Staphylococcus aureus (28% of the patients), Pseudomonas aeruginosa (19%), and Staphylococcus sp (9%). Clinical success was observed in 91% and 87% of the CIP-and PNH-treated patients, respectively. At 1-month follow-up, 4% of CIP and 6% of PNH patients showed a relapse of otorrhea. Bacteriologic eradication was seen in 89% and 85% of patients in the CIP and PNH groups, respectively. At 1-month follow-up, reinfection or recurrence of infection appeared in 3 patients in the PNH group and in 1 patient in the CIP group. Both treatments were well tolerated. The most frequently reported adverse events were pruritus, stinging, and earache. Audiometric tests did not show changes attributable to study drugs in any but 1 patient in the PNH group. This clinical trial shows that topical 0.2% ciprofloxacin solution in single-dose containers is effective and well tolerated in patients with chronic suppurative otitis media.