A method of removing mercury from flue gases from combustion plants, such as for example power plants or waste incineration plants, is achieved in which mercury-containing flue gases are brought into contact with an adsorption reagent either directly or indirectly by being contained in an absorption reagent, whereby mercury is substantially adsorbed by the adsorption reagent during this contact. After adsorption has occurred the adsorption reagent is separated from the flue gases and subsequently from the absorption reagent and added to an aqueous solution containing an oxidizing agent, whereby the adsorbed mercury dissolves as Hg.sup.2+. The Hg.sup.2+-containing solution is subsequently separated from the adsorption agent and the Hg.sup.2+ then is removed from the solution. This method enables the mercury to be removed from flue gas in a simple and economical manner.