**1. Introduction**

The narration of discovery of Nanodiamonds is highly interpreted by the inventor V.V. Danilenko. Over a period of two decades, Nanodiamonds accidently produced three times by Russian scientists through explosion. Initially, Nanodiamonds developed as single diamond particles (having diameter 4–5 nm). Later on Nanodiamonds used as an alternative for semiconductor quantum dots for biomedical imaging. Subsequently, Nanodiamonds used as magnetic sensors, composites, biomolecules and drugs, surface chemistry, other areas in medicines also. At the end of twentieth century, Nanodiamonds or ultrafine-dispersed diamonds (UDD) originated through an ignition of larger masses [1]. Nanotubes, fullerene, 3D, 2D, 1D nanosheets composed of carbon materials captivate young researchers toward wide range of applications. Recently Nanodiamonds (NDs) which is also carbon based material fascinating the world of science. Nanodiamonds is basically composed of carbon having sp3 hybridization possess elevated chemical and physical properties [2].

Nanodiamonds can be produced through different process namely diamond microcrystals, high pressure high temperature (HPHT), chemical vapor deposition (CVD), laser ablation, detonation technique, autoclave synthesis, electron irradiation of carbon onions, chlorination of carbides, and ultrasound cavitation. Laser ablation, detonation technique, and high energy ball milling of diamond by HPHT methods were using economically. We require large quantities of Nanodiamonds for research and application level studies. In this chapter we are discussing about Nanodiamonds, production of Nanodiamonds, its structure and properties, applications in major areas.
