Background: The objective of this study was to test the psychometric properties of the Polish version of the Individual Work Performance Questionnaire (IWPQ). Material and Methods: The study was conducted on 3 independent samples of 1582, 581 and 40 individuals employed as manual workers, social service and white collar workers. To test the IWPQ structure an exploratory factor analysis was conducted. Multigroup confirmatory factor analysis and invariance test were carried out among subgroups. The reliability was assessed by means of Cronbach’s α coefficient (internal consistent) and test–retest (stability over time) method, with a 4-week follow-up. The construct validity of the IWPQ was tested by means of correlation analysis, using work engagement, positive and negative affect at work, and job burnout as the criterion variables. Results: The Polish version of the IWPQ displays very good internal consistency, theoretical validity, and test–retest stability. The results of the factor analysis confirmed a 3-factor structure of the questionnaire. Construct invariance across subgroups was confirmed. Task performance was negatively correlated with negative affect at work, job burnout and positively correlated with work engagement and positive affect at work. Contextual performance was negatively related with counterproductive work behaviors, negative affect at work and positively related with work engagement. Conclusions: The Polish version of the IWPQ – like the original scale – consists of 18 items and has 3 subscales. Despite certain limitations the Polish version of the IWPQ shows good psychometric properties and it can be used to measure individual work performance in Polish conditions. Med Pr Work Health Saf. 2023;76(5):389–98.