The word'nano'is derived from Latin word, which means dwarf.Nano size refers to one thousand millionth of a particular unit thus nanometer is one thousand millionth of a metre.Nanotechnology is the science that deals with the processes that occur at molecular level and of nanolength scale size.There are numerous examples from nature like DNA,water molecules,virus,red blood corpuscles (RBC) etc. which are of nanodimensions;even our history has numerous examples which prove that we have exploited the advantages of technology in one or other form.The term nanotechnology has been most commonly used in other fields of science like electronic, physics and engineering since many decades. Nanotechnology has shown tremendous progress in these fields.However, biomedical and pharmaceutical fields remain yet to be explored.Nanotechnology is a multidisciplinary field, convergence of basic sciences and applied disciplines like biophysics, molecular biology,and bioengineering.It has created powerful impact in various fields of medicine including cardiology,ophthalmology,endocrinology, oncology,immunology,gene delivery, brain targeting,tumor targeting, and oral vaccine formulations.