Literature Review: The use of mindfulness techniques has gained popularity over the last two decades or so, and increasing amounts of research are being undertaken in the field. There now exists a range of literature to support the use of mindfulness techniques in clinical practice with a range of populations. The current research leaves many questions unanswered, particularly the need for a clear definition and exploration of what the concept of mindfulness is and how and why training in mindfulness works. The following review describes the existing research around mindfulness training and explores the different therapeutic models which incorporate aspects of mindfulness in clinical interventions. Limitations of the current literature are discussed and directions for future research are suggested. Empirical Paper: The literature on mindfulness as a clinical intervention has rapidly expanded in recent years but questions about its use and effectiveness remain unanswered, one of which concerns the active agents of change. The current study aimed to investigate two specific techniques which currently form part of larger mindfulness training packages: mindful breathing and the body scan. 59 university undergraduates were recruited and were tested on a number of measures of stress tolerance, psychological symptoms and affect, as well as attention and mindfulness skills. A range of mixed design ANOVA statistics are calculated but no significant effect of training in either technique is reported. These results are discussed in terms of their implications for future research and clinical interventions. The study suggests that non-specific factors, such as membership of a group, might be important in the success of mindfulness training.