The number of refugees and internally displaced persons in need of protection and assistance has increased from 30 million in 1990 to more than 43 million today. War and civil strife have been largely responsible for this epidemic of mass migration that has affected almost every region of the world, including Europe. Since 1990, crude death rates (CDRs) during the early influx of refugees who crossed international borders have been somewhat lower than CDRs reported earlier among Cambodian and Ethiopian refugees. Nevertheless, CDRs among refugees arriving in Ethiopia, Kenya, Nepal, Malawi, and Zimbabwe since 1990 ranged from five to 12 times the baseline CDRs in the countries of origin. Among internally displaced populations in northern Iraq, Somalia, and Sudan, CDRs were extremely high, ranging from 12 to 25 times the baseline CDRs for the nondisplaced. Among both refugees and internally displaced persons, death rates among children less than 5 years of age were far higher than among older children and adults. In Bangladesh, the death rate in female Rohingya refugees was several times higher than in males. Preventable conditions such as diarrheal disease, measles, and acute respiratory infections, exacerbated often by malnutrition, caused most deaths. Although relief programs for refugees have improved since 1990, the situation among the internally displaced may have worsened. The international community should intervene earlier in the evolution of complex disasters involving civil war, human rights abuses, food shortages, and mass displacement. Relief programs need to be based on sound health and nutrition information and should focus on the provision of adequate shelter, food, water, sanitation, and public health programs that prevent mortality from diarrhea, measles, and other communicable diseases, especially among young children and women.