People living in mountain ecosystems in the developing world are particularly vulnerable to climate change as a result of their high dependence on natural resources for their livelihoods, comparatively higher exposure to extreme events, and widespread poverty and marginalisation. However, little is known about the impacts of climate change on these communities, people’s perceptions of change, or their capacity to adapt. In order to identify the key determinants for future adaptation, we need to have a much better understanding of these issues. This publication provides an analytical framework and methodology for assessing environmental and socioeconomic changes affecting the livelihoods of rural, natural resource dependent communities living in mountainous environments. It also gives guidance on how to gain a better understanding of the forces which shape mountain communities’ vulnerabilities, and the capacities inherent to these communities for coping and adapting. The framework is intended primarily for development practitioners and institutions working on climate change vulnerability and adaptation in mountainous environments.