Hospital-acquired pneumonia is defined as pneumonia that appears for the first time within 48 h of hospital admission. Special care is needed in treatment because of poor patient conditions, including the underlying disorder, immunocompetence and general status. The 2002 hospital-acquired pneumonia guidelines were reviewed, and the current revisions were made based on those findings with the aim of producing simple and practical guidelines. Differences are seen between hospital-acquired pneumonia in the USA and Japan, and hospital-acquired pneumonia treatment guidelines matched to circumstances in Japan were considered necessary.