Hydrogen is widely billed as the fuel of the future. For this to be a reality there is a pressing need for a safe, economic and reliable way to transport hydrogen, particularly for automotive applications. This has prompted a world-wide effort to develop novel materials that are re-usable and capable of storing and releasing significant (> 6 wt%) quantities of hydrogen. In addition to compressed (either liquid or gaseous) hydrogen, two main themes are being explored: adsorption of hydrogen by materials and "chemical hydrogen" where hydrogen is reacted with a material. The discussion focusses on both themes, from synthesis and characterisation to application of such novel materials. The focusses on the wider issues involved in synthetic routes, characterisation, materials properties, rather than simply on examples. The importance of the interplay of theory and experiment is stressed. Faraday Discussion 151, organised by the Faraday Division, aims to bring together the diverse range of workers in the field of hydrogen storage materials, from those involved in materials discovery and characterisation, to those studying mechanisms or developing applications. The Discussion will both inform people of alternative strategies and encourage new ideas and approaches. The themes cover: application of theory and spectroscopic methods to understand hydrogenation/dehydrogenation mechanisms; novel approaches such as catalysed hydrogenation/dehydrogenation of organic molecules, encapsulation of nanosized materials in carbon or polymers; chemical hydrogen: characterisation and properties of main group and transition metal borohydrides and alanates, ternary and quaternary metal hydrides, reactive hydride composites; adsorbed/physisorbed hydrogen on or in MOFs, promoted carbons and other materials with large internal or external surface area; and applications including uses for automotives and novel battery materials.