comorbid psychological factors affect the experience and prognosis of chronic pain, as comorbidity is associated with poor treatment outcomes and greater levels of disability (burns, johnson, mahoney, devine, & pawl, 1998; holzberg, robinson, geisser, & gremillion, 1996; tunks, crook, & weir, 2008). cognitive variables, such as anxiety sensitivity (as) and fear of pain, have been associated with functional impairment (e.g., gheldof et al., 2010; plehn, peterson, & williams, 1998). one theory put forward is that as is a vulnerability factor for the development of fear of pain (keogh & asmundson, 2004). the present study examined whether a cognitive-behavioural intervention that included a component targeting as led to a reduction in functional impairment in participants with chronic pain. ninety-six participants were recruited from several pain clinics. following a screening procedure, eligible participants were assigned to either the 12-week treatment group or the control group, and completed questionnaire packages pre-treatment, post-treatment, and at a three month follow-up. results partially supported the hypotheses made. although there was no direct relationship between change in as or fear of pain and functional impairment, participants did report a reduction in fear of pain following treatment. exploratory analyses were conducted examining the relationship between therapeutic alliance (ta) and treatment outcome, and initial hypotheses made were supported, as participants who completed measures at all three time points demonstrated that higher levels of ta were associated with more self-control over pain and less catastrophizing. strengths and limitations, along with clinical implications of the findings and directions for future work are discussed.