As a result of their mobile lifestyle, migrant children experience a high degree of unpredictability in all aspects of their lives. This paper illustrates how the patterns of migrant families’ moves put their children at even greater risk for educational problems than is true for other mobile student groups, such as dependents of U.S. military personnel. Migrant families tend to move more frequently and in more erratic patterns than military families. Other characteristics of migrant families and their lifestyle are identified that, when combined with mobility, make migrant children’s needs unique, and more dire, than those of other marginalized student subgroups. These characteristics are (1) poverty, underemployment, low income, and child labor; (2) social and geographic isolation; (3) language and cultural barriers that impede migrant families’ communication with schools and community service providers; (4) low level of parental education, which lessens parents’ involvement in their children’s education; (5) limited access to federal assistance; (6) illegal immigration status, which limits access to services; (7) lack of protection with regard to occupational safety and health, labor disputes, and child labor; and (8) poor health status of migrant children, including higher rates of work-related injuries, acute conditions, and infectious diseases. (Contains 45 references.) (SV)