The psychological flexibility model appears to be useful for organizing research into chronic pain. One component of the model is called "cognitive defusion." A process referred to as decentering, measured by the Experiences Questionnaire (EQ), appears similar to cognitive defusion. The purpose of this study is to extend previous investigations of the EQ, to evaluate its factor structure, and examine both indirect and direct roles for decentering in relation to key clinical outcomes. 352 people seeking pain treatment participated in this study. All completed the EQ and standard measures of daily functioning, including emotional functioning. Confirmatory factor analysis (CFA) and structural equation models (SEMs) were utilized to examine the factor structure of the EQ and evaluate the role of decentering in relation to outcomes. In CFA the overall fit of the EQ items to a two-factor model, specifying decentering and rumination factors, was poor. Separate models of decentering (a higher order model consisting of two sub-factors; cognitive defusion and self-a-context) and rumination, including reduced item sets, yielded good statistical fits. Analyses of these factors showed expected relations with emotional and social functioning but not with physical functioning. SEM revealed that both decentering and rumination have direct effects on functioning and indirect effects through measures of acceptance. A shortened 12-item measure of decentering warrants further study. Combined models of acceptance and the type of cognitive-defusion-related process reflected in decentering may improve our understanding social and emotional functioning in relation to chronic pain.