This study examined the relations between disability, as measured by the Pain Disability Index (PDI) and self-efficacy, fear avoidance variables (kinesiophobia and catastrophizing), and pain intensity, using a prospective design. Two primary health care samples (n(1) = 210; n(2) = 161) of patients with subacute, chronic or recurring musculoskeletal pain completed sets of questionnaires at the beginning of a physiotherapy treatment period. Multiple hierarchial regression analyses showed that self-efficacy explained a considerably larger proportion of the variance in disability scores than the fear avoidance variables in the first sample. This finding was replicated in the second sample. Pain intensity explained a small, but significant proportion of the variance in disability scores in one sample only. Gender, age, and pain duration were not related to disability. These findings suggest that self-efficacy beliefs are more important determinants of disability than fear avoidance beliefs in primary health care patients with musculoskeletal pain. The findings also suggest that pain-related beliefs, such as self-efficacy and fear avoidance, in turn, are more important determinants of disability than pain intensity and pain duration in these patients. (C) 2004 International Association for the Study of Pain. Published by Elsevier B.V. All rights reserved.