OBJECTIVE A prospective study was designed to assess the most relevant prognostic factors influencing outcome in children treated with antibiotics for recurrent acute otitis media (AOM). METHODS A prospective study was performed in 69 patients with recurrent AOM who received prophylactic treatment in the Pediatric Otorhinolaryngology Section of our hospital between January 1998 and May 1999. In all patients, 17 variables were registered: age, sex, family history of recurrent AOM, history of prematurity, history of allergies, use of day care centers, household smokers, maternal smoking, coincidence with dental eruption, symptoms of upper respiratory obstruction (snoring, breathing through the mouth, obstructive tonsils), episodes of tonsillitis per year, age at first AOM episode, season in which prophylaxis was started, and characteristics of neonatal feeding (breast or bottle feeding and position). ResultsThe mean age was 35.3 months (range: 9-120 months). There were 38 boys (55.1 %) and 31 girls (44.9 %). The factors related to a more favorable response to treatment were lower age at the first AOM episode (p 0.004) and a positive family history of AOM (p 0.047). CONCLUSIONS The children that benefitted most from the prophylactic schedules for recurrent AOM were those that had the first episode at an earlier age and who had a positive family history of the disease.