The success of the synthesis of dendritic polymers was first reported in the early 1980s (Newkome et al., 1985; Tomalia et al., 1985). Dendritic polymers are now commonly referred to as dendrimers, which have a highly branched, three-dimensional, nanoscale architecture with very low polydispersity and high functionality, comprising a central core, internal branches, and a number of reactive surface groups (Figure 19.1). Further, the number of branches and surface groups exponentially increases along with the generation, thus allowing for high drug payload and multimodality. The emergence of dendrimers has greatly expanded the pool of carriers for drug delivery and led to the development of more efficient drug delivery systems. Because of their unique structure and properties, dendrimer drug delivery is undergoing rapid development. This chapter not only traces the evolution of the field of dendrimers in drug delivery but also reflects the journey through the subject from inception to contemporary progress.