Interventions for chronic low back pain (CLBP) often attempt to modify patients' levels of catastrophizing, their fear-avoidance beliefs, and their appraisals of control. Presumably, these interventions are based on the notion that changes in these cognitive factors are related to changes in measures of adjustment. The aim of the present study was to explore whether changes on these cognitive factors were related to changes in CLBP and disability. Fifty-four CLBP patients completed a series of self-report measures prior to beginning a cognitive-behavioral based intervention and again upon discharge. Change scores (post-treatment score minus pre-treatment score) were calculated for each of the self-report measures. The study found that changes in the cognitive factors were not significantly associated with changes in pain intensity. In contrast, reductions in fear-avoidance beliefs about work and physical activity, as well as increased perceptions of control over pain were uniquely related to reductions in disability, even after controlling for reductions in pain intensity, age and sex. The final model explained 71% of the variance in reductions in disability.