The purpose of this review is to critically appraise pain assessment tools for non-communicative persons in intensive care available in the literature, and to determine their relevance for those with brain injuries. Nursing and medical electronic databases were searched to identify pain tools, with a description of psychometric proprieties, in English and French. Seven of the ten tools were considered relevant and systematically evaluated according to the criteria and indicators in the following five areas: conceptualization, target population, feasibility and clinical utility, reliability, and validity. Results indicate a number of well-designed pain tools, but additional work is necessary to establish their accuracy and adequacy for brain injured non-communicative persons in intensive care. Recommendations are made for selecting the best tool for clinical practice and for research.