The main objective of writing this article is to put the emphasis on the importance of Nano structured based drug delivery systems. Although drugs as such can be delivered in the body using different routes but most of the routes have its own limitations like poor solubility, absorption, first pass metabolism and poor bioavailability, hence need for this nanostructured based drug delivery systems was developed. This technique not only will help us in overcoming the above mentioned drawbacks but also this helps us in reducing the dose, systemic side effects and in addition to these, this also helps us in delivering the drugs to the site of action. These Nano based systems can be used to deliver variety of drugs through different routes of administration including oral, topical, transdermal, ocular and parenteral. This review also overcomes some problem of solid lipid Nano particles like drug expulsion during storage, drug loading capacity. This review outlines the process involved in the types of NLC’s, excipients, preparation of NLC’s, its characterization and evaluation and its pharmaceutical applications.