The heat exchangers in all types of coal-fired power plant operate in aggressive, high temperature environments where high temperature corrosion can severely limit their service lives. The extent of this corrosion is governed by the combined effects of the operating conditions of the heat exchanger and the presence of corrosive species released from the coal during operation. This paper reviews the coal-related factors, such as ash deposition, which influence the operating environments of heat exchangers in three types of coal-fired power plant - conventional pulverized coal boilers, fluidized bed boilers and coal gasification systems. The effects on the performance of the materials used for these heat exchangers are then compared. (au) 35 refs.