Despite an ever increasing array of antimicrobial agents and an expanding vaccination program, infectious diseases remain an important cause of morbidity and mortality in children. This issue will address some of the most important contemporary issues in pediatric infectious diseases, with emphasis on clinical presentation, prevention, and therapy. General chapters on immunization and chemotherapy (antiviral, antibiotic, antiparasitic, and antifungal) will be complemented by discussion of common clinical syndromes, including otitis media, pharyngitis, bronchiolitis and pneumonia, gastroenteritis, bone and joint infections, meningitis, and periodic fevers.