Chronic neck pain (CNP) is a common and disabling condition, accounting for substantial healthcare and societal costs. Previous studies have demonstrated that certain cognitive factors are related to levels of adjustment (levels of disability, pain and depression) in chronic pain conditions. However, this association has not been adequately explored in patients with CNP. The aim of study one was to determine the relationship between specific cognitive factors and levels of adjustment in participants with CNP. Furthermore, study two explored whether the relationship between the cognitive factors and levels of adjustment differed between those patients with idiopathic CNP and those with Chronic Whiplash Associated Disorder (CWAD). Finally, study three compared the efficacy of a physiotherapy led intervention, specifically designed to modify cognitive factors to a conventional physiotherapy intervention.Study one: Hierarchical multiple regression analyses were performed. Greater catastrophizing and lower functional self-efficacy beliefs were associated with greater levels of pain and disability. Additionally, lower functional self-efficacy beliefs were also associated with greater levels of depression. Study two: Data were dichotomised into two groups: those with CWAD and those with idiopathic CNP. T-tests were performed to compare differences in the cognitive scores and the same regression analyses as study one were performed for each sub-group. No significant differences existed between the two groups in terms of levels of pain, disability, depression or the cognitive factors. In both groups greater catastrophizing and lower functional self-efficacy beliefs were related to levels of disability. Likewise, lower self-efficacy beliefs were related to levels of depression in those participants with idiopathic CNP and those with CWAD. However, amongst those with idiopathic CNP, greater levels of catastrophizing and lower levels of pain vigilance and awareness were related to greater pain intensity. In contrast, amongst those with CWAD, none of the cognitive measures were significantly related to levels of pain intensity.Study three: Participants were randomly allocated to either a progressive neck exercise programme or an intervention which specifically targeted the modification of cognitive factors. T-tests revealed that treatment targeting cognitive factors resulted in greater improvements in pain and pain-related fear. Moreover, Χ2 tests revealed that a greater proportion of patients made clinically meaningful reductions in pain and disability in the group targeting cognitive factors. This thesis highlights that cognitive factors play an important role in determining levels of adjustment in patients with CNP. Furthermore, treatments designed to specifically target these factors result in superior clinical outcomes when compared to conventional physiotherapy interventions.