In recent years, the search of renewable and clean energy attracted great attentions from politicians as well as scientists, due to several factors including global warming, health problems and oil prices. Hydrogen is very promising as clean and renewable energy resource; therefore its use will improve significantly air quality, health as well as prevents global warming, caused by fossil fuels. Hydrogen have been stored as pressurized gas (high pressures vessels and risk of explosion) and as liquid using cryogenic vessels (energy of liquefaction, leaks), or an atomic “solid”, e.g. in the form of a hydride (high density, reversible, safe). Hydrogen Storage Materials (HSM) synthesized at the nanoscale regime attracted great attention in recent years due to their high hydrogen capacity and improved thermodynamic properties. In this paper, several types of materials will be presented and discussed in terms of synthesis, characterization and their corresponding thermodynamic properties (hydrogen capacity, desorption temperature, kinetics, etc), including conventional intermetallic hydrides (LaNi5, FeTi), Mg-based materials, carbon nanostructures and finally light complex hydrides.