Clinical perfectionism has been implicated as a transdiagnostic construct involved in the aetiology, maintenance, and course of a wide range of Axis I disorders. Typically characterised by the setting of unrealistically high standards for performance, perfectionism has been suggested to be associated with a number of negative psychological outcomes. Moreover, it has been suggested that the process in which perfectionists set and strive for their high performance standards, including the way in which they revaluate such standards, may be maintained by a number of maladaptive cognitive, affective, and behavioural constructs. However, how such factors may differ across adaptive and maladaptive dimensions of perfectionism remains unclear. This article reviews the adaptive and maladaptive conceptualisations of perfectionism and critically examines the empirical literature pertaining to the cognitive-behavioural model of clinical perfectionism. In addition, we also review outcomes of intervention studies that have focused on altering dysfunctional cognitions when treating clinical perfectionism. Clinical implications of these findings and directions for future research are also explored.