Intensive interdisciplinary pain treatment (IIPT) is a successful functional restoration approach for children with complex and disabling chronic pain based on significant improvements in self-report measures. However, little research has examined change in performance-based measures or the relationship of those changes to self-report assessments. This study examined both self-report and performance-based measures of physical function among N=210 IIPT patients. Results showed contributions of both types of measures to predicting functional disability at program admission and discharge. Slightly different aspects of the pain experience may be captured by self-report versus performance-based measures; both are important to more fully understand improvement in disability among pediatric patients with chronic pain undergoing IIPT.