The aim of the study was to evaluate the efficacy of short-course antimicrobial therapies [single intramuscular dose of ceftriaxone (50 mg/kg, not exceeding 1 g), 5 days of azithromycin (10 mg/kg on day 1, then 5 mg/kg daily on days 2-5) and the traditional 10-day course of amoxicillin/clavulanate (90/6.4 mg/kg/day in 2 doses)] in children with acute otitis media (AOM). The study was conducted as a prospective, comparative, open randomized trial between February 2001 and April 2003, and 104 children were enrolled, with a mean age of 3.8 (2.3) years. The clinical and otoscopic assessments of the children were made on days 0, 3, 11 and 30 after admission, and tympanometry was performed on day 30. The patients were diagnosed and followed with a scoring system. Clinical success was achieved in 29/34 patients (85.3%) in the ceftriaxone group, 27/31 patients (87.1%) in the azithromycin group and 34/39 children (87.2%) in the amoxicillin/clavulanate group. The rate of persistence of middle-ear fluid did not differ between the three groups (p>0.05). During the one-month period, no recurrent case was observed. The most common drug-related adverse effects were associated with the gastrointestinal system. In conclusion, for the treatment of children with AOM, the clinical success of single-dose intramuscular ceftriaxone and of five-day azithromycin treatments was comparable to that of the traditional 10-day therapy with high-dose amoxicillin/clavulanate.