The authors reviewed literature on the health of voluntary migrants to Western societies and factors affecting their health. Health indicators include mortality rates and life expectancy, birth outcomes, risk of illness, patterns of deteriorating health, cardiovascular disease, body mass index, hypertension, and depression. Multiple factors explain variability, including length of residence and acculturation, disease exposure, life style and living conditions, risky behaviors, healthy habits, social support networks, cultural and linguistic barriers, experiences with racism, and levels of awareness of cultural health practices among health care providers. Evidence exists for superior health among many migrants to Western countries relative to native-born persons, but the differential disappears over time. Migration is a dynamic, extended process with effects occurring years after physical relocation. Systemic change is required, including health policies that ensure equity for migrants, culturally appropriate health promotion, and routine assessment of migration history, cultural health practices, and disease exposure.