Livelihoods in the Himalayas have traditionally depended on a multitude of strategies, using available ecosystem services, but also typically encompassing external activities like trade and labour migration. Changes in ecosystem services due to environmental or socio-economic change affect mountain livelihoods, and so are likely to impact migration. Yet the impacts of environmental stressors are super-imposed on the local socio-economic setting and, generally, exacerbate existing household vulnerabilities. Differential vulnerability within and between communities is the consequence of unequal exposure to shocks and stress, sensitivity of livelihoods and inequalities in terms of adaptive capacity. Depending on the scale of damage, adaptive capacity of affected households and communities, issue of safety and security, availability of material assistance, and extent of livelihood disruption, mountain households can adopt one or more livelihood strategies from a portfolio of responses, which may include migration. Moreover, favourable environmental conditions along with the development of transport and communication infrastructure in some parts of mountainous regions have also created employment opportunities not just for local populations, but also migrant workers from within mountain regions and from the neighbouring lowlands. Migration in these circumstances can therefore have several forms: displacement, labour migration, household migration, or community resettlement. This chapter explores these different forms of migration, drawing on existing literature on the Himalayan region. It seeks to understand the extent to which environmental stressors and drivers are important to migration in the context of a range of other drivers.