This chapter analyses the relationship between migration and health, demonstrating that health is a key indicator of migrants' integration. It is organised in five sections. The first section describes the types of research carried out so far on this topic. The second section discusses the main determinants of health and the determinants particularly relevant for migrants. The third considers the evidence regarding the health of different groups of migrants. The fourth section examines the main issues that migrants' health raises for state policies and healthcare organisations. The fifth and concluding section reviews the questions that remain regarding migrants' health.