Cognitive aids are prompts designed to help users complete a task or series of tasks. They may take the form of posters, flowcharts, checklists, or even mnemonics. It has been suggested that the use of cognitive aids improves performance and patient outcomes during anesthetic emergencies; however, a systematic assessment of the evidence is lacking. The aim of this literature review was to determine (1) whether cognitive aids improve performance of individuals and teams and (2) whether recommendations can be made for future cognitive aid design, testing, and implementation. Medical, nursing, and psychology databases were searched using broad criteria to find cognitive aids that have been reported in the literature for use in anesthetic emergencies. The reference lists of the articles selected for review were also screened to identify additional studies. Selected articles that described the evaluation of cognitive aids used in anesthetic emergencies were reviewed to determine how the content of the aid was derived, how the design was evaluated, and the success of the aid in improving technical and team performance. The search yielded 22 cognitive aids developed to support clinicians during anesthetic emergencies that had been evaluated in 23 studies. Ten studies using simulation suggested that technical performance improves with the use of cognitive aids in some anesthetic emergencies such as malignant hyperthermia, cardiopulmonary resuscitation, and airway management. However, in 3 of the simulator-based evaluations, participants had either no improvement or took longer to diagnose and treat and made more incorrect diagnoses. Four studies investigated the effect of the aids on teamwork with differing conclusions. One study suggested improved participants coordination patterns and one found aids improved their decision-making scores, but 2 other studies indicated that there was no improvement and even provided evidence of reduced levels of team communication when teams used a cognitive aid in simulated conditions. The designs of cognitive aids were rarely considered. Education may compensate for a poorly designed aid, but only by ingraining correct actions for situations in which the aid provides little or no guidance. Cognitive aids should continue to be developed from established clinical guidelines where guidelines exist. They would also benefit from more extensive simulation-based usability testing before use. Further evidence is required to explore the effects of cognitive aids in anesthetic emergencies, how they affect team function, and their design considerations. Copyright ? 2013 International Anesthesia Research Society.