Generalised Anxiety Disorder (GAD) is highly debilitating and one of the most prevalent anxiety disorders. Although there is evidence that Cognitive Behavioural Therapy alleviates symptoms in GAD to some extent, GAD remains the anxiety disorder for which an evidence-based range of treatment is poorest. Given that GAD is extremely prevalent and costly, both on an individual and societal level, development of efficacious treatments for GAD is critical. One possible reason for the relative scarcity of effective treatments in GAD might be that the mechanisms underlying maintenance of the disorder are not sufficiently understood. Thus, in order to develop effective treatments, the mechanisms maintaining the disorder need to be identified and examined. Drawing on key theoretical models and emerging empirical evidence, I will first discuss possible maintenance mechanisms in GAD, and highlight discrepancy-based processing, worry and avoidance as emotional dysregulation strategies. I will then go on to discuss possible clinical implications of such mechanisms. In particular, I will explore the merit of Mindfulness-Based Cognitive Therapy (MBCT) for GAD. MBCT belongs to the wider group of treatment interventions that are Mindfulness-Based Cognitive Interventions (MBIs) and focus on training the capacity to relate to aversive stimuli with curiosity, non-striving and self-compassion. I will discuss the theoretical rationale for implementing MBCT in GAD, especially considering the theoretical backdrop of recurrent depression, and critically review the empirical evidence for the efficacy of MBCT in GAD. I conclude that there is preliminary, but promising, evidence that MBCT has merit in GAD, both on a general level of anxiety symptoms, but also studies indicating a possibility of targeting more specific maintaining mechanisms. Directions for future research will be discussed.