Polyoxometallates, a typical metal-oxygen cluster system, have great potential for electro-catalytic applications, since the window of the redox potential of the species can be easily varied with the nature of the heteroatom and the addendum atoms. This presentation considers the application of these species for a few selected electro-catalytic reactions and demonstrates how these species can be appropriate for applications like hydrogen peroxide sensing, methanol oxidation, and oxygen reduction reaction, which has great relevance for the so-called energy conversion devices namely fuel cells. In addition to energy conversion devices, they can also be employed for energy storage in the form of suitable material for super capacitor electrode material. © Panch Tattva Publishers, Pune, India 2013. All rights are reserved.