Diatoms are unicellular golden brown algae. They are unique nano-structured silica structures whose size range from 2µm to 500µm. They are responsible for fixing 25% global CO2. They have solved the crisis of global warming by being one of the major energy providers in the form of crude oil to produce gasoline and the yield of bio-fuel from diatoms alone is responsible for 30% crude oil deposited along earth’s ocean floors. Due to their silica cell wall they are used as nano-material in various fields of science in cell biology, bio-energy, drug industry, as semi-conductors besides having optical properties.Among wide applications presently we are much focused on oil from diatoms by engineering them metabolically as well as via Nano fabrication and opened our ways towards diatoms as a drug vehicle in treating various antibacterial as well as carcinogenic diseases.