The Handbook “Monitoring Prison Violence” was developed in the framework of the EU Project ‘Improving judicial cooperation across the EU through harmonised detention standards – the role of National Preventive Mechanisms’ implemented by the Ludwig Boltzmann Institute of Fundamental and Human Rights (Austria), in cooperation with the Associazione Antigone (Italy), the Bulgarian Helsinki Committee (Bulgaria) and Hungarian Helsinki Committee (Hungary). It is part of a series of 4 handbooks on prison monitoring and a dossier on systemic thinking in preventive human rights monitoring. The Handbook provides a practical tool for improving the understanding of: the thematic issue of violence and the risks associated with it, the existing international standards on violence and those pertaining to its prevention, and how to apply these international standards in practice and effectively prevent and monitor violence. It was written with the aim to raise awareness among NPMs on certain topics which, during the course of the Project, were identified as important factors for enhancing their work and their impact in terms of preventing violence.