OBJECTIVE To describe the washout effect after stopping a prevention checklist for ventilator-associated pneumonia (VAP). METHODS VAP rates were prospectively monitored for special cause variation over 42 months in a paediatric intensive care unit. A VAP prevention bundle was implemented, consisting of head of bed elevation, oral care, suctioning device management, ventilator tubing care, and standard infection control precautions. Key practices of the bundle were implemented with a checklist and subsequently incorporated into the nursing and respiratory care bedside flow sheets to achieve long-term sustainability. Compliance with the VAP bundle was monitored throughout. The timeline for the project was retrospectively categorised into the benchmark phase, the checklist phase (implementation), the checklist washout phase, and the flowsheet phase (cues in the flowsheet). RESULTS During the checklist phase (12 months), VAP bundle compliance rose from <50% to >75% and the VAP rate fell from 4.2 to 0.7 infections per 1000 ventilator days (p<0.059). Unsolicited qualitative feedback from frontline staff described overburdensome documentation requirements, form fatigue, and checklist burnout. During the checklist washout phase (4 months), VAP rates rose to 4.8 infections per 1000 ventilator days (p<0.042). In the flowsheet phase, the VAP rate dropped to 0.8 infections per 1000 ventilator days (p<0.047). CONCLUSIONS Salient cues to drive provider behaviour towards best practice are helpful to sustain process improvement, and cessation of such cues should be approached warily. Initial education, year-long habit formation, and effective early implementation demonstrated no appreciable effect on the VAP rate during the checklist washout period.