Brucellosis is considered the most widespread zoonosis in the world. Although reported prevalence of the disease varies widely from country to country, bovine brucellosis caused mainly by Brucella abortus is still the most prevalent. Brucella melitensis is the principal cause of brucellosis in sheep, goats and camels. This same organism is the cause of undulant fever in humans. Brucellosis is still a major disease problem in the Mediterranean region, western Asia, parts of Africa and Latin America. Reduction in human brucellosis cases is a good indicator of successful progress in the control of animal brucellosis. The zoonotic significance of brucellosis therefore requires concerted efforts for control through intersectoral collaboration between ministries of agriculture-veterinary/health-medical and other stakeholders. Such collaboration depends to a large extent on the availability of science-based information collected through efficient surveillance systems for the purpose of designing practical and feasible control strategies to reduce the prevalence of the disease and where feasible, to eradicate it. These guidelines have been prepared with that aim. They have been developed by reviewing programmes in countries that have successfully controlled and eradicated brucellosis as well as in those countries where the disease is still endemic. In using these guidelines for human and animal brucellosis surveillance it must be emphasized that what has been successful in one country may not necessarily be successful in another, based on factors such as level of control of animal movement, socio-cultural practices and traditional preferences. It is therefore suggested that these guidelines be adapted to suit prevailing local conditions and animal management systems in order to achieve set goals.