Abstract Environmental health problems associated with metals in developing countries are complex and frequently severe. They relate to the mining of mineral deposits in these countries, the smelting of metal-containing ores, and the secondary smelting of batteries and electronic waste products transported into these countries for recycling. Despite efforts in the international community to promote sustainable development, these activities are frequently conducted in developing countries under conditions of limited health and safety regulation due to the limited resources available to implement environmental and occupational health standards in many developing countries. Poor nutrition and a general lack of food are also contributory factors that exacerbate susceptibility to metal toxicity. These issues are further compounded by metal contamination of food crops through the utilization of cadmium-containing phosphate fertilizers, arsenic in irrigation water from contaminated groundwater, and other metals or chemicals from industrial or municipal wastewater sources. The economies of developing countries are often highly dependent on the mining, smelting, and recycling of metals, as well as on agricultural products, so tighter regulation of ongoing practices is frequently a secondary concern. This multiplicity of factors combines to create an overall situation that frequently places populations in developing countries at an elevated risk of adverse public health outcomes from metal exposures. However, it also should be noted that, given the increased globalization of industries and the food supply, metal contamination of the environment in developing countries with aeolian transport of metals in the atmosphere, ocean currents, and food may also present potential public health problems to populations in developed countries. For these reasons, the issues discussed in this chapter are generic and global in nature.