Community-acquired pneumonia is one of the commonest and deadliest of the infectious diseases, yet our understanding of it remains relatively poor. The recently published American Thoracic Society and Infectious Diseases Society of America Community-acquired pneumonia guidelines acknowledged that most of what we accept as standard of care is supported only by low quality evidence, highlighting persistent uncertainty and deficiencies in our knowledge. However, progress in diagnostics, translational research, and epidemiology has changed our concept of pneumonia, contributing to a gradual improvement in prevention, diagnosis, treatment, and outcomes for our patients. The emergence of considerable evidence about adverse long-term health outcomes in pneumonia survivors has also challenged our concept of pneumonia as an acute disease and what treatment end points are important. This review focuses on advances in the research and care of community-acquired pneumonia in the past two decades. We summarize the evidence around our understanding of pathogenesis and diagnosis, discuss key contentious management issues including the role of procalcitonin and the use or non-use of corticosteroids, and explore the relationships between pneumonia and long-term outcomes including cardiovascular and cognitive health.