Ingoing streams (coal, limestone powder, process Hp) and outgoing streams (fly ashes from three stages of electrostatic precipitator, slag, gypsum, sludge and sewage from desulfurization system) were analyzed for elemental compn. to develop material balances of particular 58 elements. Materials were derived from Polish coal-fired power plant equipped with a 3-stage electrostatic precipitator and wet flue gas desulfurization system. The elemental compn. of coal combustion products mostly depended on the coal compn. The rare earth elements were concd. mainly in the sludge from wet desulfurization, while Ca, S, Ge and Se in the gypsum and in the sludge.