BACKGROUND: functional assessment is an important component of the management of older adults in the emergency department (ED) as the function level has been identified as a predictor of adverse events including ED re-presentation. A systematic review (SR) of all functional assessments utilised in EDs has not been undertaken making assessment selection, on the basis of evidence, difficult for staff. OBJECTIVE: this SR: (i) identified functional assessments that have been utilised in ED settings, (ii) examined what psychometric properties analysis has been completed and (iii) established recommendations for practice. METHODS: electronic database searching was completed utilising key search terms. Articles were reviewed using pre-determined inclusion criteria. Each study was appraised using quality criteria for aspects of validity and reliability in addition to clinical utility, interpretability and responsiveness. Recommendations for practice were determined on the basis of the extent of psychometric data generated in ED settings and whether or not the assessment was specifically developed for ED use. RESULTS: a total of 332 articles were identified of which 43 articles utilising 14 functional assessments were retained. Psychometric testing was scarce. Functional assessment has been reported internationally and only with older adults. Following appraisal four assessments [the Identification of Seniors at Risk (ISAR), Triage Risk Stratification Tool (TRST), Older Adult Resources and Services (OARS) and Functional Status Assessment of Seniors in Emergency Departments (FSAS-ED)] were recommended for practice with moderate reservations. CONCLUSION: the ISAR or TRST are suitable for fast screening, whereas the OARS or FSAS-ED are more suitable for a comprehensive understanding of functional performance. Further research is warranted and recommendations for ED assessment may change as more becomes known about psychometric properties and clinical applications of other assessments.