Concept of nanotechnology refers to study of characteristics of materials ranging between 0.1 to 100 nanometer. It also refers to fabrication of such materials and relevant calibration technology with the help of carbon nanotube field effect transistors(CNTFET), nano powders and others. With the help of this technology revolutionary nanomachines like nanorobots, DNA computers and nano computers can be formed. Effective check on cancer would also be possible by this, thereby reducing the pain due to side effects of regular radiation therapies and chemotherapies presently used. Nanotechnology promises to make us healthy and wealthy. It can have biggest impact on medical science.