We present a study of acute otitis media among 20,532 Spanish children during a 6-month period from January through June 1991. The study was done by distributing a questionnaire to all Spanish pediatricians. Of the patients 51.7% were girls and 48.3% boys; 68.7% of all children were younger than 5 years. The most frequent symptoms were otalgia or irritability, 92.7%; fever, 63.5%; otorrhea, 24.9%; vomiting, 21.4%; and another concomitant upper respiratory tract infection, 65.5%. Otitis was bilateral in 45.6% of the cases. The most frequently used antibiotic was cefixime (38%), followed by amoxicillin-clavulanate (22.2%), amoxicillin (15.3%), 2nd-generation cephalosporins (13.5%) and macrolides (8.8%). In 11.8% of the patients, a change in the initial antibiotic therapy was required due to adverse effects. Resolution of symptoms occurred in 77.8% of the patients.