BACKGROUND Acute external otitis (AEO) is a painful condition that results as a secondary infection of macerated skin and subcutaneous tissues of the external auditory canal. The most commonly causative microorganisms are Pseudomonas aeruginosa and Staphylococcus aureus. Classic management strategies include moisture prevention, cleansing of the canal and administration of topical antimicrobial agents in drop form, such as aminoglycosides and quinolones, at times in combination with steroid solutions. The objective of this study was to evaluate and compare the efficacy of topical otic powder, tobramycin drops and ciprofloxacin drops in patients suffering from AEO. MATERIALS AND MEASURES: A randomized prospective trial was performed to determine the efficacy of Auricularum powder (dexamethasone 10 mg, oxytetracycline HCl 90,000 U, polymyxin B Sulfate 100,000 U, nystatin 1,000,000 U; Trima, Serolam Laboratories, Germany) compared with ciprofloxacin (Ciloxan, Alcon Laboratories, Fort Worth, TX) and tobramycin (Tobrex, Alcon Laboratories) drops for the treatment of AEO. One hundred twenty patients who presented with signs and symptoms of AEO were enrolled. Inclusion criteria were: AEO diagnosed by an otolaryngologist, patient age 18 years, no prior treatment with other drops or systemic antibiotics, no sensitivity to any of the drugs used or their contents, and no perforation of the tympanic membrane. All patients were instructed to avoid moisture and wetness of the ear during the course of their treatment. After we received informed consent, a swab culture was taken, and the patient was randomly assigned topical treatment for 14 days. RESULTS Eighty-six percent of those treated with Auricularum powder were cured at day 3-4 after initial treatment. Seventy-seven percent of those treated with ciprofloxacin drops, and fifty-six percent of those treated with tobramycin were cured at that time. All 120 patients were cured by day 14. CONCLUSIONS The results show that topical treatment with Auricularum powder is an effective and rapid method for the treatment of AEO. Ciloxan also was effective in the treatment of AEO and relieved symptoms quickly and efficiently in a short period of time. Tobrex was effective in treating AEO, but our results show that relief of symptoms was slower than with the other drugs.