The role of microalloying has changed over the years as the range of products where used has expanded and the production processes have improved.When used in the early ferrite-pearlite steels,its chief function was grain refinement and precipitation hardening.Later,as the quest for higher strength led to bainitic and martensitic microstructures,the role of microalloying changed to grain refinement and transformation control.Later still microalloying has been successfully applied in martensitic and the advanced high strength steels grades for automobiles.The goal of this paper is to follow this changing role of microalloying in both conventional and advanced steels from the 1960s until today.