AimThe Abilitator is a self-assessment questionnaire which was developed to evaluate the perceived work ability and different aspects of functioning of working-age people. The present study aimed to explore the concurrent validity of the Abilitator.Subject and methodsThe participants (n = 177) were patients of a rehabilitation outpatient clinic. Their mean age was 47.1 years. Using Spearman’s correlation coefficients, we assessed the concurrent validity of the Abilitator to compare it to the HAD, RAND-36, EQ-5D, and WHODAS 2.0 (12-item short version) questionnaires.ResultsThe five domains of the Abilitator showed fair to moderate correlation coefficients with the previously validated and accepted measures of functioning. The strongest correlations were found in specific domains measuring similar constructs, namely social inclusion and RAND-36 vitality/fatigue (rs = 0.58), psychological functioning and RAND-36 emotional well-being (rs = 0.67) and HAD depression (rs = −0.65), everyday activities and total score of EQ-5D (rs = 0.63), cognitive functioning and WHODAS 2.0 cognition (rs = 0.57), and physical condition and RAND-36 physical functioning (rs = 0.70). Analysis by subpopulations of gender and age group showed a broadly similar pattern to that of the total sample. In general, stronger correlations were seen among women and among those of a younger age (50 years or under).ConclusionThe Abilitator questionnaire has acceptable concurrent validity for assessing different aspects of the functioning of working-age people.