BackgroundThe assessment of work ability with reliable, thoroughly tested instruments, is central to evidence-based occupational therapy practice.Aims/ObjectivesThe aim of this study was to investigate the psychometric properties of the Finnish version of the WRI with a focus on construct validity and measurement precision.Material and MethodsNinety-six WRI-FI assessments were performed by 19 occupational therapists in Finland. A Rasch analysis was conducted to evaluate the psychometric properties.ResultsThe WRI-FI presented an overall fit to the Rasch model, with good targeting and separation among persons. The four-point rating scale structure was supported by the Rasch analysis, except for one item with disordered thresholds. The WRI-FI indicated stable measurement properties across gender. Seven of the 96 persons showed misfit, which slightly exceeds the criteria of 5%.ConclusionsThe findings from this first psychometric evaluation of the WRI-FI provided evidence of construct validity and support for measurement precision. The hierarchy among items corresponded with previous studies. The WRI-FI can offer occupational therapy practitioners a valid tool to evaluate psychosocial and environmental perspectives of persons work ability.