Base-catalyzed reaction between a thiol and an epoxide group is a simple fusion process that leads to the formation of a b-hydroxythio-ether linkage. This reaction is efficient, regio-selective, and fast. In addition, it produces a reactive hydroxyl group upon completion. Therefore, it is of considerable potential in synthesis of reactive and functional soft materials. Here, we discuss the fundamental aspects of this process, the so-called thiol-epoxy "click" reaction, and its utility in the preparation and post-polymerization functionaliza-tion of polymers and crosslinked networks. Furthermore, its application in surface modification of solid substrates is also considered. Finally, utility of multifunctional materials created using the thiol-epoxy reaction is discussed in the biomedical arena.