This study investigated prospective links between quality of the early caregiving environment and children's subsequent executive functioning (EF). Sixty-two families were met on five occasions, allowing for assessment of maternal interactive behavior, paternal interactive behavior, and child attachment security between 1 and 2 years of age, and child EF at 2 and 3 years. The results suggested that composite scores of parental behavior and child attachment were related to child performance on EF tasks entailing strong working memory and cognitive flexibility components (conflict-EF). In particular, child attachment security was related to conflict-EF performance at 3 years above and beyond what was explained by a combination of all other social antecedents of child EF identified thus far: child verbal ability and prior EF, family SES, and parenting behavior. Attachment security may thus play a meaningful role in young children's development of executive control.