Objective To systematically retrieve,evaluate and integrate the best evidence on the prevention and management of aspiration in critically ill adult patients and had it summarised to form the best evidence so as to provide an evidence-based reference for prevention and management of aspiration.Methods Following the"6S"pyramid model,literatures on prevention and management of aspiration in critically ill adult patients published from January 2013 to August 2023,were retrieved from databases of BMJ Best Practice,UpToDate,Joanna Briggs Institute Evidence-Based Healthcare Centre in Australia,College of Nurses of Ontario in Canada,International Guideline Network,Guidelines.gov of the United States,National Institute for Health and Care Excellence,Scottish Intercollegiate Guidelines Network,PubMed,Embase,Cochrane Library,CINAHL,Chinese Clinical Practice Guidelines Library,Medlive,Chinese Biomedical Literature Database,CNKI,Wanfang Data and VIP.The retrieved data included clinical decisions,guidelines,evidence summaries,expert consensus/recommendations,systematic reviews/meta-analyses,and randomised controlled trials regarding the prevention and management of aspiration in critically ill adult patients.Two researchers who were trained in evidence-based nursing independently conducted literature selection,quality assessment,evidence extraction and synthesis.Results A total of 33 articles were included,with 4 clinical decisions,4 guidelines,5 evidence summaries,8 expert consensuses,9 systematic reviews/meta analysis and 3 randomised controlled trials.Eventually,36 points of best evidence were summarised from 9 themes,namely aspiration risk assessment,airway management,oral hygiene management,positioning management,enteral nutrition management,drug management and prevention,diagnosis and treatment of aspiration,prevention of post-extubation aspiration,aspiration training,and team management.Conclusions This evidence summary can provide healthcare workers with evidence-based support for prevention and management of aspiration in ICU,which will make ICU nursing more scientific and standard.