Intensive Care Med (2009) 35:9–29DOI 10.1007/s00134-008-1336-9 Although thousands of papers have been devoted tohospital-acquired pneumonia (HAP), many controversiesremain, and management of HAP is probably often sub-optimal. Several reviews or guidelines have been pub-lished recently, mostly by North American initiatives(CDC, ATS). Three European Societies (ERS, ESCMID andESICM) were interested in producing a document thatcould complement in some way the last IDSA/ATS guidelines published 3 years ago. In addition, the Helics working group supported this initiative.