Supported by the MacArthur Foundation, ICIMOD undertook a series of research activities together with partners in the Eastern Himalayas from 2007 to 2008 to provide a preliminary assessment of the impacts and vulnerability of this region to climate change. Activities included rapid surveys at country level, thematic workshops, interaction with stakeholders at national and regional levels, and development of technical papers by individual experts in collaboration with institutions that synthesised the available information on the region. A summary of the findings of the rapid assessment was published in 2009. The present publication is the main synthesis report, and is accompanied by a CD-ROM with six technical papers on climate change projections, biodiversity, wetlands, water resources, hazards, and human wellbeing. Much more, and more precise, information will be needed to corroborate the present findings. Nevertheless, the assessment highlights the vulnerability of the Eastern Himalayan ecosystems to climate change as a result of their ecological fragility and economic marginality. It is hoped that it will both inform conservation policy at national and regional levels, and stimulate the coordinated research that is urgently needed