In penal institutions stress is present in the prisoner population as well as prison staff which is constantly exposed to specific requirements of the job. The burn out syndrome is common among prison staff because of the high stress that they are dealing with. People that suffer the burn-out syndrome are less productive, negative towards their job and they can have problems on a personal plan. The job in prison is dynamic, it includes making important decisions, working with heavy population and it often includes reduced physical safety because of the possible rebellion. On the other hand, prison population is going through stress caused by incarceration, separation from family and friends and changing the environment in which the person will be spending it’s days. Also, there is a danger of violence in prison. Therefore, it is important to keep positive psychosocial climate in the institution so the prisoners and the staff could feel safer and better. Mindfulness techniques are becoming popular in psychology, medicine, education, business world, but also in penal institutions. The goal of this paper is to explore the effects of mindfulness practices among prison population and staff in penal institutions, and to explore effect of the mindfulness based programs. According to the previous researches mindfulness techniques have a beneficial effect on reducing the symptoms of depression, anxiety, stress, reducing addiction relaps and improving well-being, interpersonal relationships and skills related to coping with stress. Practicing mindfulness techniques also reduces aggression, impulsivity and at the end it can prevent recidivism with prison population.