Background: Few formal instruments exist to assess the communicative competence of patients hospitalized in intensive care units (ICUs). This can limit interventions by health professionals. Aims: To map the categories and instruments for assessing the communicative competence of adult patients with minimal response in ICUs. Methods & Procedures: A scoping review was carried out following the Joanna Briggs Institute protocol between February and March 2022 and using the MEDLINE (PubMed), Scopus, Scielo, Business Source Complete (via EBSCOhost), Academic Search Complete (via EBSCOhost) and Web of Science databases, in Portuguese, English and Spanish. Main Contribution: Eight studies met the inclusion criteria. The different communication and pain assessment protocols covered awareness, cognition, sensory capacity, motor capacity, language, speech and literacy. Conclusions & Implications: The present review offers a starting point for the construction of a formal assessment instrument to enable clinicians to implement an augmentative or alternative communication system (AACS) for the voluntary, independent and active participation of patients.