Doctors Without Borders/Médecins Sans Frontières (MSF) has sections in 19 countries. Five of these sections are considered 'operational sections', meaning that they directly control field projects—deciding when, where, and what medical relief is necessary and, eventually, when to terminate aid. These sections are: Belgium, France, Holland, Spain, and Switzerland.

The remaining 13 MSF sections are 'non-operational'. The primary functions of a non-operational section are to recruit volunteers, to raise funds for field projects, and to do public outreach and education projects on behalf of populations in danger. Branch offices are located in: Australia, Austria, Canada, Denmark, Germany, Greece, Hong Kong, Italy, Japan, Luxembourg, Norway, Sweden, the UK, and the U.S. MSF has four other offices which are: an international office in Brussels; UN Liason Offices in Geneva and New York City; and an office in United Arab Emirates.

Three specialized public-health centers—Epicentre, Aedes, and HealthNet—work with MSF to further expand its expertise in practical epidemiology and the management of health-care programs. Epicentre's findings are published in journals such as the Journal of the American Medical Association and The Lancet. Most of the World Health Organization's disaster training is done at Epicentre.