Over the past decade, there has been an increasing interest in using nanotechnology for cancer therapy. The development of smart targeted nanoparticles (NPs) that can deliver drugs at a sustained rate directly to cancer cells may provide better efficacy and lower toxicity for treating primary and advanced metastatic tumors. We highlight some of the promising classes of targeting molecules that are under development for the delivery of NPs. We also review the emerging technologies for the fabrication of targeted NPs using microfluidic devices.