The study of migrant populations poses unique challenges owing to the mobility of these groups, which may be further complicated by cultural, educational, and linguistic diversity as well as the legal status of their members. These barriers limit the usefulness of both traditional survey sampling methods and routine public health surveillance systems. Since nearly 1 in 7 people in the world is a migrant, appropriate methodological approaches must be designed and implemented to capture health data from populations. This effort is particularly important because migrant populations, in comparison to other populations, typically suffer disparities related to limited access to health care, greater exposure to infectious diseases, more occupational injuries, and fewer positive outcomes for mental health and other health conditions. This path-breaking handbook is the first to engage with the many unique issues that arise in the study of migrant communities. It offers a comprehensive description of quantitative and qualitative methodologies useful in work with migrant populations. By providing information and practical tools, the editors fill existing gaps in research methods and enhance opportunities to address the health and social disparities migrant populations face in the United States and around the world.