Multifunctional dendrimers have attracted great attention in drug delivery and targeting owing to their outstanding physicochemical properties. Surface modification of dendrimers is an important aspect, which could be achieved using conjugation chemistry in association with different interaction mechanisms. All these strategies make them more suitable for safe and effective delivery systems in addition to minimisation of the toxicities associated with the bioactive(s). This book chapter exhaustively discussed the numerous conjugation processes, chemistry and interaction mechanisms for therapeutic delivery.