Poly(amidoamine) dendrimers (PAMAM) are novel polymeric highly branched architectures with well-defined nano-size, narrow polydispersity index and numerous active amine functional groups at the periphery. The highly attractive feature of modifiable multiple surface functionalities facilitates conjugation of various ligands for cancer targeting, imaging and therapy. As well as, solubilization, high drug encapsulation, inherent passive targeting ability will also contribute to the therapeutic success of dendrimers. Cancer researchers are very eager about the utility of PAMAM dendrimer as a drug carrier and non-viral gene vector. This review highlighted the potential of non-targeted and ligand targeted surface engineered PAMAM dendrimers for the delivery of anticancer drugs and gene therapeutics and briefly focus on the diagnostic imaging applications of PAMAM dendrimers.