BACKGROUND: Professionally, private security guards are expected to manage their anger and stress successfully. OBJECTIVE: The primary purpose of this study is to determine stress and anger levels of private security guards working in the Ankara Electricity, Gas and Bus Operations Organization. The secondary aim of this research is to determine the effectiveness of the training program given to private security guards within the scope of anger and stress control. The effects of training on 690 private security guards who participated in the training program were investigated. METHODS: In the first part of the study, the validity and reliability of the Trait Anger, Anger Expression Scale and Coping with Stress Scale were investigated, and in the second part, the effectiveness of training given to 690 private security guards was examined. Also, as a comparison group, 201 private security guards who did not participate in the training were reached and the scales were applied. RESULTS: The results showed that private security guards had an inability to cope with stress and anger was triggered easily. The average treatment effect was E[Y(1) - Y(0)| X] = -0.111 and statistically significant. It shows that training had a significant effect on anger. Anger decreased when stress-coping behaviours increased and the training was effective. CONCLUSIONS: It is important that training about anger and stress control should be given to security forces at regular intervals.