The United Nations defines non-governmental organisations as “All organisations [...] that are not central governments and were not created by intergovernmental decision, including associations of businesses, parliamentarians and local authorities”.

In the context of medical peace work you will encounter NGOs such as such as Médecins Sans Frontières and the International Committee of the Red Cross, as well as Oxfam, Save the Children and a host of nationally-based humanitarian and development NGOs.