Arsenic and fluoride are recognized as the most toxic inorganic contaminants in water resources that require the implementation of cost-effective treatment processes and materials for their removal. In this context, slags have been evaluated to remove arsenic individually, but to the best of our knowledge the simultaneous removal of both pollutants has not been performed. The aim of this work is to evaluate the performance of four types of iron and steel slags for the simultaneous removal of arsenic and fluoride present at high concentrations in water. Batch adsorption tests were carried out at room constant temperature and natural pH to determine the capacity of these materials to remove these pollutants. Two treatment stages with steel slag produced an effluent with residual concentrations of As and F lower than the limits established for drinking water.