This study is an attempt to build a narrative on social capital of mountain communities that is possibly changing under the combined influence of multiple stressors, including climate change, in the Hindu Kush Himalaya region. Using data from the International Center for Integrated Mountain Development large-scale surveys in the region, the study presents a baseline pattern for institutional dependence of mountain communities to address basic needs, to access productive resources, to access extension services, and to get social support. The five case studies presented in the study are expected to tell us whether changes in sources of social capital are likely to influence the baseline pattern of institutional dependence. This study looks at three sources of social capital of rural mountain communities: (1) mutual trust within communities along with reciprocity between communities, (2) norms underlying customary law and practice for natural resource management, and (3) informal networks among farmers. What emerges from the case studies is the proposition that the Hindu Kush Himalaya region is possibly witnessing a process of simultaneous decay and emergence of social capital in the mountain communities, which has implications for adaptation planning and governance. Public authorities would need to take this process of change in social capital to effectively harness the synergy arising out of state-society linkage and plan for adaptation interventions tailored to the context.