The 2009 Gordon Conference on Hydrogen-Metal Systems continues the premier advanced research series on the broad subject of interactions between hydrogen and metals. First started in 1981, this biennial science conference has grown in importance and popularity as the R&D world attacks the great challenges of implementing “Hydrogen Energy”, a possible long-term solution to both petroleum supply limits and global warming. The Conference addresses cutting-edge research topics such as complex and metallic hydrides, modeling of H-M thermodynamics and reaction pathways, metal-catalyzed hydrogenation and dehydrogenation of reversible H-storage media (carbon and other adsorbents or absorbents), H-M surface science, nanomaterials, test techniques and hydrogen effects on the mechanical performance of structural metals. This Conference will be of interest to scientists, young and old, at the forefront of this field. Throughout the years, H-M Systems has been an excellent means of bringing together experienced scientists, junior scientists and graduate students in the unique open and informal environment of the traditional Gordon Conference. There will be many opportunities for all attendees to hear ground breaking invited presentations and to participate in formal group discussions, as well as informal one-on-one interactions during free afternoons and meal periods. One of the most important parts of the Conference will be contributed posters showing very new results. In 2007, 100 posters were presented on an impressive spectrum of H-M subjects. A limited number of poster presenters will be offered the option of presenting a short oral summary of their poster before their respective session. This is the first time H-M Systems will be held in Europe, in recognition of the major contributions European and other International Scientists have made to this field, and especially this Gordon Conference, over the last quarter-century.