In the past decade, severe community-acquired pneumonia (CAP) has been established as a clinical syndrome of its own, with peculiar features in epidemiology, risk, and outcome. As a result, severe pneumonia requires a distinct clinical approach and initial antimicrobial treatment. In this article, current knowledge about the definition, epidemiology, criteria for intensive care unit (ICU) admission, diagnostic evaluation, outcome and prognosis, as well as antimicrobial and nonantimicrobial treatment of severe CAP, is reviewed. An epidemiologic (empiric) initial approach is advocated, which may be modified by results of microbial investigation in the individual case.