Introduction The use of functional assessments to evaluate patient change is complicated by a lack of consensus as to which assessment is most suitable for use with older adults. Objective: To identify and appraise the properties of assessments used to evaluate functional abilities in older adults. Methods A systematic review of randomised controlled trials of occupational therapy interventions was conducted up to 2012 to identify assessments used to measure function. Two authors screened and extracted data independently. A second search then identified papers investigating measurement properties of each assessment. Studies from the second search were included if: i) published in English, ii) the assessment was not modified from its original published form, iii) study aim was to evaluate the quality of the tool, iv) and was original research. Translated versions of assessments were excluded. Measurement quality was rated using the COSMIN checklist and Terwee criteria. Results Twenty-eight assessments were identified from the systematic search of occupational therapy interventions provided to older adults. Assessments were of varied measurementquality and many had been adapted (although still evaluated as though the original tool had been administered) potentially altering the conclusions drawn about measurement quality. Synthesis of best evidence established 15 functional assessments have not been tested in an older adult population. Conclusions The Functional Autonomy Measurement System (SMAF) appears to be a promising assessment for use with older adults. Only two tools (the SMAF and the Assessment of Motor and Process Skills (AMPS)) were deemed to be responsive to change when applied to older adults. Health professionals should use functional assessments that have been validated with their population and in their setting. There are reliable and valid assessments to capture the functional performance of older adults in community and hospital settings, although further refinement of these assessments may be necessary.