The determination of the content of ecotoxic elements directly in flue gas is important for determining its actual emission from coal combustion. Moreover, in the BAT for large combustion plants conclusions adopted in 2017, apart from tightening of pollutants emission standards, i.e. SO 2, NO x and dusts, and setting emission limits, among others, for mercury, the monitoring of the actual emission of toxic elements has been established with the use of specific analytical methods. The review and comparison of available methods of analyzing the content of elements in flue gases in accordance with American and European standards has been presented in the article. Moreover, the factors influencing the quality of the obtained measurement results were identified.