The early childhood years are critical for developing executive function (EF) and theory of mind (ToM). Prior literature suggests a robust relationship between EF and ToM; however, this relationship has seldom been investigated in children living in poverty. In addition, few studies have employed comprehensive ToM measures to explore how EF relates to different components of ToM. This study examined longitudinal relations between EF and ToM among 86 preschool children (3- to 5-year-old) attending Head Start programs in the United States. Children completed two EF tasks and a 5-task ToM battery twice, four months apart. (author abstract)