Community-acquired pneumonia (CAP) is a major cause of morbidity and mortality worldwide especially among young children and the elderly. The financial burden caused by CAP varies widely depending on the economic development of the society, and on the health care system. Early diagnosis, appropriate antibiotic treatment and early admission of more severely ill patients to observational units are key factors to improve outcome of CAP patients. This book summarises the current knowledge about all aspects of CAP. The Editors have succeeded in attracting leading experts within the field to write chapters which provide an overview from current knowledge to future developments that are on the horizon.