This study examined the effect of significant weight gain on physical, demographic, behavioral, and psychosocial factors in a representative sample of chronic pain patients. One hundred fifty-five chronic pain patients who reported gaining more than 15 pounds since the onset of their pain were compared with 341 pain patients who stated that their weight had remained the same since the onset of their pain. All patients were given a medical examination and each patient completed a comprehensive pain questionnaire and an SCL-90. Results showed that a significant relationship exists between weight gain and decreased physical activity, increased emotional distress, and accident liability. This study suggests that the inclusion of weight management training in multidisciplinary pain centers may play an important part in the rehabilitation of chronic pain patients