Psychological treatments in secure settings have traditionally been based on psychodynamic and cognitive–behavioural approaches. Recent developments, supported by an emerging evidence base, have generated a significant amount of interest in mindfulness-based psychological therapies and their utility in diverse areas of mental healthcare. In this article we analyse the current evidence base and describe possible mechanisms of action of mindfulness-based psychological approaches. On the basis of the evidence, we advocate a cautious but positive approach to using mindfulness-based interventions in secure services.