The amount of child migration in the part of Kenya is substantial and knowledge of its impact on child health outcomes could inform child health programs and interventions. Most of the research on child migration has focused on older children who left home to work in settings that are potentially hazardous or exploitative or on the migrant behaviour of the parents. The results showed that child migration was not a risk factor for mortality. Indeed, in-migrant children from urban areas had a lower risk of mortality compared with non-migrant children. Asembo and Gem in Nyanza Province, one of the provinces with the worst child survival outcomes in Kenya, the demographic surveillance area of the Kisumu Health and Demographic Surveillance System (KHDSS) has high rates of both in-migration and out-migration for children. The core of the KHDSS consists of house-to-house interviews conducted on a rolling basis through three rounds in each calendar year.