Objective. The aims of this study were to examine the internal structure of the Spanish version of the Chronic Pain Acceptance Questionnaire and present new empirical evidence regarding its validity. Design and Methods. A sample of 315 chronic pain patients attending a pain clinic completed a battery of instruments to assess pain acceptance, general psychological acceptance, depression, anxiety, pain intensity, functional impairment, and current functioning. Results. Confirmatory factor analysis supported the validity of a 20‐item version with two subscales corresponding to two independent factors: Activity Engagement and Pain Willingness. Structural Equation Modelling showed that the association between pain intensity and anxiety and depression was fully mediated by Activity Engagement which partially mediated the association between pain intensity and functioning. Pain Willingness partially mediated the influence of pain intensity on functional impairment. Conclusions. These findings indicate the differential influence of both components on adjustment to chronic pain.