Throughout the world pneumonia remains an important infectious disease among all age groups, ranking high in terms of mortality, morbidity, and use of medical resources. However, the introduction of antibiotics has had a major impact on the management and mortality of pneumonia. As a clinical syndrome it is constantly changing with the emergence of new pathogens and the rising prominence of opportunistic pathogens in the immunocompromised patient. Developments in science have resulted in a greater understanding of microbial virulence and host defenses as well as new chemothera peutic agents. However, the single most common pathogen responsible for pneumonia remainsStreptococcus pneumoniae,an organism for which there is a vaccine. This review highlights some recent advances in the epidemiology, etiology, pathogenesis, management, and prevention of pneumonia.