© 2018 Association for Contextual Behavioral Science This paper provides preliminary data on a new questionnaire known as the Everyday Psychological Inflexibility Checklist (EPIC). Contextual Behavioural Science seeks to have application to human behaviour generally, not just to “psychopathology” in isolation. The field also aspires to meet some wider challenges of the human condition such as poverty, inequality, climate change and environmental destruction. It is possible that current measures, such as the AAQ-II, are not ideally suited to these wider challenges and more general measures of psychological inflexibility with different item wording may be a useful addition. As such, an initial item pool was devised which described how an individual might deal with private internal events and social interactions in a psychologically inflexible way. In the first study, data from this item pool was entered into exploratory factor analysis (EFA). This resulted in a ten item measure spread over two factors. One further item was added to bolster the second factor. In a second study, a small number of items underwent slight word changes and both old and revised versions of the measure went through further EFA. In the third study, confirmatory factor analysis (CFA) was carried out across three separate samples and a number of items were deleted, leaving seven items. The final measure produced a relativity good set of CFA fit indices. To begin to establish the contribution of the EPIC, the final study explores relationships between the EPIC, the AAQ-II and a small number of broadly prosocial measures. The discussion explores a number of issues pertinent to the current and future development of this and other measures.