Prospective, interventional, and multicentre study. The bundle consisted of seven basic mandatory measures and three highly recommended measures: strict hand hygiene, oral hygiene with CHX, and semirecumbent positioning. Implementation of the ten VAP prevention measures resulted in a significant reduction of more than 50% of the incidence of VAP in Spanish ICUs. VAP incidence density rate decreased from 9.83 per 1,000 ventilator days to 4.34 after 19-21 months of participation. Reduction of the incidence density rates were independently from hospital size.