Flue gas and fly ash are the two most important wastes from power plants. This review focuses on technologies for S02 removal from emissions and on properties and applications of fly ash. It predominantly focuses on the non-European situation; in Europe, flue gas desulfurization and ash utilization have been extensively practiced during several decades. Flue gas desulfurization (FGD) technologies are the most commonly used methods in the removal of S02 in flue gas. Factors influencing S02 removal efficiency and optimal operation conditions are considered. Physical and chemical properties of fly ash make it useable in various fields, such as cement production, concrete admixtures, soil amendment, as a low-cost adsorbent of certain types of contaminants in wastewater, and in the production of effective wastewater coagulants.