The paper reviews the current state of knowledge regarding global emissions of mercury and presents a new inventory of global emissions of mercury to the atmosphere from anthropogenic sources for the year 2000. The largest emissions of Hg to the global atmosphere occur from combustion of fossil fuels, mainly coal in utility, industrial, and residential boilers. As much as two-thirds of the total emission of ca. 2190 ton of Hg emitted from all anthropogenic sources worldwide in 2000 came from combustion of fossil fuels. Emissions of Hg from coal combustion are between one and two orders of magnitude higher than emissions from oil combustion, depending on the country. Various industrial processes account for additional 30% of Hg emissions from anthropogenic sources worldwide in 2000. Major contribution to emissions from this source category comes from gold production using Hg technology. The Asian countries contributed about 54% to the global Hg emission from anthropogenic sources in 2000, followed by Africa (18%) and Europe, including the European part of Russia (11%). China heads the list of the 10 countries with highest Hg emissions from anthropogenic activities. With more than 600 ton of Hg, China contributes about 28% to the global emissions of mercury. It is expected that future changes of Hg emissions from anthropogenic sources worldwide until the year 2020 should be within ±20% of the current estimates, although this assessment should be treated with great caution. Emission estimates for various continents presented in this paper were used to prepare global emission maps. These maps are presented in a companion paper (Wilson et al., 2005. Spatial distribution of global anthropogenic mercury atmospheric emissions. Atmospheric Environment, in this issue).