Abstract: Nanoparticles are the substances which fall under the nano-range and are so small that they can easily circulate in the body. There are various types of nanoparticles like liposomes, dendrimers, fullerenes, virosomes, metallic nanoparticles, silica nanoparticles, spinel ferrite nanoparticles, magnetic iron oxide nanoparticles, silver nanoparticles, Out of all the other nanoparticles gold nanoparticles are one of the particles which are highly utilized in the research work because of their non toxic and compatible nature with the human body. They are also made in such a way that it can be used as a delivery system by loading the drugs into it and can then cross various membranes and barriers to deliver the drug at the right site and also, they can be used in various diagnostic and imaging process for tumors. Depending on the use gold nanoparticles comes in various shape like that of cage, shell, rod, sphere, all of these have separate manufacturing process which could be chemical as well as organic in nature. There are mainly two approaches which are followed for manufacturing of the gold nanoparticles top down and bottom up approach. Their characterization is done using techniques of UV spectrophotometer, X-ray Diffraction, High Resolution Transmission Electron Microscopy, Dynamic Light Scattering, Surfaced Enhanced Microscopy. They find their application in use against vectors, in cardiovascular disease, in catalytic application, in hepatoprotective application, application as an anti-oxidant, in the treatment of skin cancer, in the diagnosis and therapy of Alzheimer’s disease.