Populations living in poverty in the developing world suffer a heavy burden caused by infectious diseases, most of them zoonoses. The poorer populations also tend to be marginalised from the health sector and so are many of the diseases that affect them. The poor in every society, and particularly in developing countries, bear a disproportionately high share of the disease burden. There is a broad range of viral, bacterial, mycotic, chlamydial, rickettsial and parasitic diseases of global and regional importance given their major impact on the health and socio-economic development of many populations. Endemic infectious diseases, including zoonoses, together with emerging and re-emerging diseases, are mostly shouldered by poor and vulnerable populations. Livestock are important in supporting the livelihoods of poor farmers, consumers and traders throughout the developing world. The animals of poor people are particularly vulnerable to disease because of costs, absence or unsuitability of the animal health sector, etc. The impact of endemic animal diseases are mainly felt at the farm level, while a broader economic impact can occur with these diseases through the restriction of trade in livestock and their products. Addressing comprehensive and sustainable solutions to public health problems created by endemic infections cannot be achieved solely by the public health sector alone. Partnerships with other sectors, particularly agriculture, environment, education, local administration, will be necessary to contain and effectively control zoonotic and foodborne diseases that affect mainly the poor. International organisations could support developing countries by coordinating national intersectoral activities, promoting appropriate technology and public health education, community participation and encouraging decision-makers to commit themselves. This is the only perspective for improved quality of life of poor and marginalised populations.