Most studies of retirement migration in the United States focus at the national level, and there is comparatively little information about the retirees who cross international borders in their search for new homes. Retirement migrants are unusual in that many select destinations in less-developed countries, contrary to the general pattern of migration from poor to rich countries in search of jobs, higher incomes and a better standard of life. This study has examined the reasons for retirement migration from the United States (US) to the Lake Chapala area of the Mexican state of Jalisco. A non-random sample of 211 US retirees was surveyed using a self-completion, semi-structured questionnaire that included items about the decision to move to Mexico, the quality of life at the destination, cultural adaptation, and aspects of personal identity, financial security and health-care. Four major reasons for migrating to Mexico were identified: financial circumstances, the natural environment, a sense of community and friendship, and a better quality of life. While the migrations contradict much taken-for-granted and popular knowledge about migration patterns around the world, they have important implications for the ways of life, social relationships and welfare of the most recent cohort of older people. More in-depth multidisciplinary studies are needed to increase understanding of this evolving phenomenon.