Acute otitis media (AOM) is one of the most common childhood diseases and the main reason for prescribing antibiotics in developed countries. Indiscriminate treatment of children with an inconclusive diagnosis has favored the development of resistance, and this has led to the creation of clinical guidelines to promote judicious antibiotic use. AOM has shown high rates of spontaneous resolution and minimal benefits from antibiotics; hence a policy of observation for 48-72 hours before initiating treatment is justified in many children. In recent years, attention has been focused on developing effective vaccines against the most common causative pathogens, Streptococcus pneumoniae and Haemophilus influenzae. The H. influenzae type b conjugate vaccine has little impact on AOM since most strains are nontypable. The 7-valent pneumococcal conjugate vaccine has an efficacy of 55% in AOM caused by vaccine serotypes, but replacement with nonvaccine serotypes and nontypable H. influenzae reduce the overall efficacy of the vaccine to 6-8%. An overall decrease of pneumococcal resistance to penicillin has been seen in vaccinated children, but there is a trend to an increase in antibiotic resistance in non-vaccine serotypes. High-dose amoxicillin is the treatment of choice for AOM, but the increase of H. influenzae in pneumococcal-vaccinated children may require reconsideration of this recommendation in forthcoming guidelines.