Streptococcus pneumoniae is the most common cause of community-acquired pneumonia and it is also a common cause of sinusitis, otitis media, bacteremia and meningitis. The increasing resistance to antimicrobial agents, now endemic in many countries, reflects an uncontrolled use of antibiotics. A good antibiotics policy and vaccination are at the moment the only way to control efficaciously the increasing antibiotic resistance of Streptococcus pneumoniae.