This research explored how transhumant pastoralism has been sustained and promoted in the context of socioeconomic and climate change in the mountain regions of Nepal. Based on case study research conducted in Nepal’s western mountains, the status, opportunities, and constraints of transhumant pastoralism in the changing context were analyzed. We found that indigenous and traditional knowledge, feelings of cultural identity, collective ownership, income, and mutual benefits have acted as motivating factors in sustaining transhumant pastoralism for generations. The continuation of this practice is threatened by the following challenges: the impacts of climate change on mountain ecosystems, socioeconomic changes, market influence on livelihood decisions, youth migration and labor shortage, low motivation of local people to engage in livestock rearing, and conflicts between herder and nonherder communities and institutions, as well as inadequate policy support and institutional arrangements. We conclude that unless there are positive policy and institutional arrangements to support transhumant pastoralism, the age-old practice will disappear.