Nanotechnology received a lot of attention with the never-seen-before enthusiasm because of its future potential that can literally revolutionize each field in which it is being exploited. In drug delivery, nanotechnology is just beginning to make an impact. The multidisciplinary approach of nanotechnology has opened new vistas for the development of nanoscale drug delivery systems to meet the requirements for new drug moieties. These drug moieties can either be integrated into the matrix or attached to the surface of drug delivery particles. The importance of nanotechnology in drug delivery is in the concept and ability to manipulate molecules and supramolecular structures for producing devices with programmed functions. Nanostructures like micelles, liposomes, dendrimers etc. and nanoparticles like solid lipid nanoparticles, polymeric/pegylated nanostructures, metallic nanoparticles etc. have been used to deliver drug at specific sites and reduce side effects on non target organs.