This Practical Guide was developed in the context of the OHCHR Treaty Body Capacity Building Programme, established by General Assembly Resolution 68/268 to support States parties in building their capacity to implement their treaty obligations, in this case, their obligations under the Optional Protocol. The Guide seeks to respond to key questions frequently asked about National Preventive Mechanisms (NPMs), and to explain the four core functions of the mechanisms – visiting, providing advice, enhancing cooperation and educating – which are key to their effective functioning. It also includes checklists and other guidance offering practical tools to aid their performance. The Guide aims to assist both States planning to establish or seeking to strengthen their NPMs, as well as the staff of the NPMs themselves. It should also be useful to experts and professionals involved in the prevention and combating of torture, civil society organizations and the general public. The publication builds on the recommendations of the UN Subcommittee on Prevention of Torture (SPT) relating to NPMs, which are contained in the SPT’s reports on country visits undertaken as part of its mandate, as well as key SPT documents on NPMs (annexed to the Guide).