This document provides information on the prevention, diagnosis, and treatment of community-acquired pneumonia (CAP). It discusses who is at increased risk for CAP and should receive pneumococcal and influenza vaccines. Key symptoms that should lead to consideration of a CAP diagnosis are discussed. Common causative organisms are Streptococcus pneumoniae, Haemophilus influenzae, and atypical pathogens; viruses are also often involved. Factors that increase the risk of specific pathogenic organisms are outlined.