BACKGROUND:: Activity pacing is a common intervention for patients with chronic pain. Over the past decade a number of instruments have been developed to measure this construct, but their comparative psychometric properties have not been examined. OBJECTIVE:: To review the psychometric properties of existing measures of activity pacing, and provide suggestions for future research in this emerging area of pain research. METHODS:: A narrative review of current measures of activity pacing followed by a discussion of the conceptual and psychometric challenges in this area. RESULTS:: Although there is evidence supporting activity pacing as a unitary construct, important differences remain among the various measures in terms of their item content and assumptions. All existing activity pacing measures include items that assess activity regulation, but vary in their specific content. Most importantly, questionnaire items often reflect different purposes of pacing behaviors. DISCUSSION:: Current measures of activity pacing are inadequate. New measures are needed that are based on specific theoretical models; these measures should also make the goal or intent of pacing behaviors explicit. Improvements in the assessment of activity pacing will likely lead to a better understanding of the pacing construct and the effects of pacing interventions.