Mexico's electricity-sector contributes over 75% of national SO2-emissions, causing economic and health damage. These emissions come mostly from the combustion of fossil-fuels, whereas a minor share comes from biomass (wood fuel and sugar cane) burning emissions as well as those produced by industrial processes. For this reason, this study assesses the abatement costs of several SO2-control options (including flue-gas desulphurization technologies, hydrotreatment of fuel oil, and the substitution of high-sulfur by low-sulfur content fuels). Likewise, this study has evaluated the implementation of such options in 10 selected power-plants-the main SO, emitters in the Mexican Electric Power Sector (MEPS)-with the aim of suggesting solutions for SO2-emissions reduction and estimating the corresponding abatement, investment and total costs during the analyzed period. Study's results indicate that the best SO2-abatement-costs route may account for a reduction of 41% of MEPS SO2-emissions and would require investment and total costs of $841 and $477 million, respectively. This means that an important reduction in the national SO2-emissions may be achieved with a relatively small effort. (c) 2007 Elsevier Ltd. All rights reserved.