Objectives: The aim of this scoping review was to understand the extent and type of evidence on augmentative and alternative communication tools used with mechanically ventilated patients in the intensive care unit. Review method used: This scoping review was conducted using Arksey and O'Malley's methodological framework, followed by PAGER (Patterns, Advances, Gaps, Evidence for practice and Research recommendations) framework to provide a structured approach to analysis of reviews. Data sources: In December 2021, six electronic databases-CENTRAL, CINAHL, Embase, Medline (Ebscohost), PyscINFO, and Web of Science-were searched. Searches were supplemented with hand searching of reference lists of included studies. Review methods: Studies were selected according to inclusion and exclusion criteria. Full-text review was completed by two independent authors, with any disagreement resolved by consensus or with consultation with a third reviewer. A table was developed to extract key information from the eligible studies. The Mixed Methods Appraisal Tool and Supporting the Use of Research Evidence checklist were used to quality appraise the selected primary research and reviews, respectively. Results: Twenty-three studies (19 primary studies and four reviews) were included in the review. Findings highlighted five main patterns: (i) Co-designing of the augmentative and alternative communication tools; (ii) Patients' and healthcare professionals' training needs on augmentative and alternative communication tools; (iii) Implementation of validated communication assessment algorithms; (iv) Amalgamate several communication methods/approaches; (v) Technical competency required for high-technology augmentative and alternative communication tools. Conclusion: Both low- and high-technology augmentative and alternative communication tools are widely used for mechanically ventilated patients in intensive care units, but there is a need for systematically assessing the communication needs and implementing communication interventions to promote meaningful patient-centred clinical outcomes.