Background: In the UK, CBT is currently recommended as an intervention for CFS/ME. Physical and psychological outcomes of CBT for CFS/ME vary across studies, as does the CBT model adopted. There is some evidence to suggest that some participants experience improved psychological and physical outcomes post CBT. However, the specific nature of these changes and the factors facilitating them is not well understood. This was therefore the focus of the current study. Methodology: Semi-structured interviews were conducted with 13 service users who had engaged in CBT aimed at improved management of their condition. Interviews were analysed using a grounded theory methodology, in order to build a theory of participants' experiences. Results: The theory suggests that CBT led to participants feeling more able to cope with CFS/ME. This was due to both a shift in perspective arising from the therapy room and taking a more adaptive approach to daily life. The theory also suggested that participants experienced increased acceptance of the condition, which facilitated further adaptive changes. Discussion: Findings extend existing literature in suggesting that CBT aimed to improve management of CFS/ME may result in improved coping and reduced distress, independently of changes in fatigue. Clinical and research implications are discussed.