Objectives: To compare baseline characteristics and outcomes of patients with fibromyalgia [FMS] and chronic low back pain [CLBP] participating in a cognitive-behavioral treatment program. Methods: Pretreatment and posttreatment data obtained by questionnaire from 53 participants with fibromyalgia syndrome and 57 patients with CLBP who completed a 10-session cognitive-behavioral treatment program and at one year were examined. Demographics, pain, distress, self-efficacy, disability, and symptoms of depression were measured. Results: At baseline patients with FMS and CLBP differed in a number of characteristics. Fibromyalgia syndrome patients were more likely to be female [P < .001], have higher education [P < .018], and were more self-efficacious in their ability to manage their pain [P < .027]. The CLBP patients reported higher levels of pain sensation [P < .049] and distress [P < .014], were more often prescribed opiates [P < .012], and more likely to be in litigation and receiving compensation [P < .005]. Postprogram each group reported a significant improvement in self-efficacy, pain, distress, disability, and symptoms of depression [P < .05]. There were no between group differences. Furthermore, these gains were sustained at one-year follow-up [P < .001] with no significant difference in gains made by the CLBP or FMS patients. Conclusions: Despite considerable between group differences at baseline, patients with FMS and CLBP experienced similar improvements in self-efficacy, pain, distress, disability, and symptoms of depression immediately upon completion and up to a year following a comprehensive cognitive-behavioral treatment program. [ABSTRACT FROM PUBLISHER]