Criminal behaviours can often lead to a prison sentence, and a prison sentence suggests that justice has been served. It appears that correctional facilities worldwide have been inundated with prisoners serving time for a variety of reasons. Though a prison sentence serves as punishment for perpetrators, it can often cause psychological harm for both prisoners and their families. As a result of more relevant research being conducted, several intensive rehabilitative programmes are being run in correctional facilities worldwide to address criminal behaviours such as violence. These intensive programmes aim to teach prisoners to understand the relationships between intrusive thought patterns that may or may not be associated with past traumatic events, emotional dysregulation, and poor behaviour leading to violent offending. The present study examined the impact of Mindfulness-Based Stress Reduction (MBSR) on prisoners' psychological wellbeing in correctional facilities worldwide. It was completed by running a meta-analysis on four studies based in the United States of America (USA), China, and the Netherlands and across various ethnic and cultural groups, which analysed this relationship. The results indicated that MBSR could be an effective treatment modality to run alongside intensive therapies. Furthermore, the overall effect size suggested a positive but not significant relationship between MBSR and improved psychological wellbeing. It is suggested that further research using experimental designs be explored in this field to allow for further analysis to be examined. The main objective of this review was to answer two questions: 'Is the use of MBSR in correctional facilities effective in helping reduce recidivism rates?' and 'Will the use of MBSR be effective with different cultural and ethnical populations in correctional facilities?' The conclusion of the meta-analysis in the current study suggests that yes, it is possible to reduce recidivism rates through using MBSR as an effective treatment in correctional facilities. Furthermore, it can be successfully implemented across people of different cultures and ethnicities.