The paper discusses technology for sulfur dioxide (SO2) pollution control by flue gas cleaning (called 'scrubbing') in the utility industry, a technology that has advanced significantly during the past 5 years. Federal Regulations are resulting in increasingly large-scale applications for control of coal-fired boilers. With much less fanfare, control of SO2 in industrial process waste gases has been in use for some time in various industries. At first most applications were motivated by economic or aesthetic reasons; later, more by various pollution control regulations. Although the utility industry is responsible for most of the SO2 emissions, emissions from other industrial sources may have a greater effect, percentagewise, on ambient SO2 concentrations in populated areas. This is due mainly to height of the point of release of the waste gas (stack height), generally higher for utility systems (point sources) than for SO2 sources (area sources). With respect to combustion of sulfur-bearing fuels, accounting for more than 75% of the SO2 emissions, three basic control approaches can be taken: burn low-sulfur fuel, treat the fuel to reduce its sulfur content, and treat the waste gas to remove SO2. This paper concentrates on the third approach; treating waste gas to remove SO2.