The importance of prison staff training is recognised in the European Prison Rules. Working in a prison environment that involves working with a hostile population, workplace hazards, shift work, and overtime requires selected professional staff who undergo quality basic and advanced training and education. Education/training is the foundation of prison workers’ professionalism and influences the development of people skills and understanding of the behaviour of prisoners, as well as support for the rehabilitation of prisoners. Training of prison staff has a long tradition in Slovenia. The training of prison workers in Slovenia is primarily regulated by the Enforcement of Criminal Sanctions Act, which implements the guidelines and recommendations of the Council of Europe and the United Nations on the enforcement of prison sentences. In contrast to the training of prison officers, which is precisely defined in the legislation, the definition of training for treatment workers is vague but demands highly educated individuals with knowledge of human behaviour, sociology, social work, and psychology,