This study attempts to understand local people’s perceptions of climate change, its impacts on agriculture and household food security, and local adaptation strategies in the Hindu-Kush Himalayan (HKH) region, using data from 8083 households (HHs) from four river sub-basins (SBs), i.e. Upper Indus (Pakistan), Eastern Brahmaputra (India), Koshi (Nepal) and Salween and Mekong (China). The majority of households in SBs, in recent years, have perceived that there have been more frequent incidences of floods, landslides, droughts, livestock diseases and crop pests, and have attributed these to climate change. These changes have led to low agricultural production and income, particularly in Eastern Brahmaputra (EB) where a substantial proportion of HHs reported a decline in the production of almost all staple and cash crops, resulting in very low farm income. Consequently, households’ dependency on external food items supplied from plain areas has increased, particularly in the Upper Indus (UI) and EB. After hazards, households face transitory food insecurity owing to damage to their local food systems and livelihood sources, and constrained food supply from other areas. To cope with these, HHs in SBs make changes in their farming practices and livestock management. In EB, 11 % of HHs took on new off-farm activities within the SB and in SM, 23 % of HHs chose out-migration as an adaptation strategy. Lastly, the study proposes policy instruments for attaining sustainable food security, based on agro-ecological potential and opportunities for increasing agricultural resilience and diversity of livelihoods.