Both self-efficacy and fear-avoidance beliefs have been shown to be predictors of the level of disability in low back pain suffers. What is not clear from the literature, however, is whether the two constructs are differentially predictive of disability. The aim of this study was to investigate the relationship between pain self-efficacy and fear-avoidance beliefs and to determine whether they can explain unique variance in disability scores. One hundred and twenty-one people over the age of 18, suffering from chronic low back pain and receiving workers' compensation, completed the Pain Self-Efficacy Scale (PSEQ), the Fear Avoidance Beliefs questionnaire (FABQ), the Quebec Back Pain Disability Scale and a visual analogue scale for pain. The results show that, after controlling for pain, self-efficacy explained 24% of the variance in disability scores, and fear avoidance only a further 3.1%.