Over the past decade, experimental and longitudinal research has shown that psychological flexibility is an important determinant of mental health and behavioural effectiveness in the workplace. These findings have been established using a general measure of this psychological process, the Acceptance and Action Questionnaire-Revised (AAQ-II). Consistent with Acceptance and Commitment Therapy (ACT) theory, psychological flexibility may demonstrate even stronger associations with variables related to a work context (e. g., job satisfaction) if it were assessed using a measure of the construct that is tailored to the workplace. To test this hypothesis, we first developed such a measure, the work-related acceptance and action questionnaire (WAAQ). Findings from 745 participants across three studies reveal that the structure, validity and reliability of the WAAQ are satisfactory. As predicted, the WAAQ, in comparison with the AAQ-II, correlates significantly more strongly with work-specific variables. In contrast, the AAQ-II tends to correlate more strongly with outcomes that are likely to be more stable across different contexts (e. g., mental health and personality variables). These findings are discussed in relation to ACT theory.