The history of Pediatric Infectious Diseases closely parallels the history of Pediatrics at least until the last century, because historically infections comprised the major causes of childhood morbidity and mortality, as they still do in the developing world. This history reviews developments in the field through the centuries and is written so that it does not overlap the contribution to this series by Baker and Katz entitled 'Childhood Vaccine Development in the United States.' Remarkable descriptions of selected pediatric infections existed long before the invention of printing, and early pediatric texts included many chapters devoted to various infections. Coincident with the establishment of pediatric organizations in America in the late 19th and early 20th Centuries, major attention was focused on diphtheria, infant diarrheal illnesses, tuberculosis, streptococcal infections and their complications, and other pediatric infections, and substantial progress was made. The American Pediatric Society (1888), the American Academy of Pediatrics (1930), the Society for Pediatric Research (1931), and the American Board of Pediatrics (1933) all contributed to the evolution of the discipline of Pediatric Infectious Disease, and numerous leaders of these organizations had significant infectious diseases interests. The establishment of the Pediatric Infectious Diseases Society, the Pediatric Infectious Diseases sub-board, and an accreditation process for training programs, as well as sub-specialty textbooks and journal, further validated the development of this specialty, particularly in North America. The many remaining challenges related to infectious diseases in children (including HIV, emerging infections, antimicrobial resistance, opportunistic infections, and infections in the developing world) insure the future of the specialty. The genomic era of medicine and the tools of molecular biology will lead to new insights into pathogenesis, diagnosis, and treatment of infections. Pediatric Infectious Diseases physicians can celebrate the past triumphs of the discipline and future achievements, all contributing to improved health for children.