Unprotected (NÀH) aziridines are the key components in several biologically active natural products and important buildingb locks in organic synthesis. However,t he synthesis of unprotecteda ziridines is much more difficult than their oxygen counterparts (epoxides). Therefore, the development of efficient routes for their synthesis represents an attractive task fororganic chemists and, as aresult, avariety of methods have been developed. In this Focus Review, we have described the various approaches that have been reportedf or the synthesis of NH-aziridines.