Nanotechnology is a field of science that deals with the nanosized materials ranging from 1 to 100nm. These nanomaterials are used in various fields such as environment, electronics, cosmetic, medicine, etc. Nowadays, the nanoparticles are widely used in the field of medicine for the purpose of drug delivery as a biological agent, chemotherapeutic agent, imaging system, immunotherapeutic agent, disease therapy, etc. They are also used in drug delivery due to its small size, larger surface area and ability to cross blood brain barriers. Nanoparticle based delivery systems are engineered based on the requirements of the disease and targeted to diseased site by active or passive targeting methods. The aim of the current paper is to discuss the application of nanoparticles in targeted drug. In this current review, various types of nanoparticles and their applications in the field of medicine are discussed.