Dendrimers are new artificial macromolecules which have the structure like a tree. They are hyperbranched and monodisperse three-dimensional molecules with defined molecular weights, large numbers of functional groups on the surface and well-established host-guest entrapment properties. Recently, dendrimers have successfully proved themselves as promising nanocarriers for drug delivery because they can render drug molecules a greater water-solubility, bioavailability, and biocompatibility. In this review, recent progress in the pharmaceutical applications of dendrimers as delivery systems for drugs, particularly, the non-steroidal anti-inflammatory, anti-microbial/anti-viral and potent anti-cancer drugs is discussed. Three possible interaction mechanisms between dendrimers and drug molecules are presented. In addition, the pharmacodynamic and pharmacokinetic properties of both dendrimer/drug complex and dendrimer-drug conjugation after their administration to animals are evaluated.