This study examines the associations between parental book reading and social-emotional outcomes for Head Start children in foster care. Despite no main Head Start impact on parental book reading, subgroup effects were found. Foster parents in Head Start provided more book reading for children with disabilities but less for children with low preacademic scores. Head Start enhanced social-emotional outcomes for children in foster care. The positive impacts of Head Start on children's social-emotional outcomes were greater when parents read books frequently. Head Start should include more foster families and provided parenting skills to enhance social-emotional outcomes for children in foster care. (author abstract)