Eliciting, evaluating and changing core beliefs are established features of cognitive behaviour therapy (CBT). However, care must be taken when working at this level of cognition. This is because therapists are dealing with core constructs that, whether dysfunctional or otherwise, influence the patient's self-concept, her world and future. This paper examines when it is appropriate to work at this level and some of the specific problems regarding assessment and the consequences of belief change. It is evident that achieving lasting cognitive change is a difficult task, and this may be in part due to the poor quality of the literature and training in the area. In an attempt to address this, the final section of the paper offers a set of practical guidelines concerning the continuum technique, a well-known CBT method for targeting, evaluating and changing core beliefs. It highlights process features (e.g. planning, management, and interpersonal skills) as being crucial in creating contexts in which change can take place. The work has been written for trainee cognitive therapists and those with a working knowledge of CBT who are seeking to improve their abilities in the use of change methodologies.