This study examined the psychometric properties and criterion validity of a newly developed battery of executive function (EF) tasks for use in early childhood. The battery was included in the Family Life Project (FLP), a prospective longitudinal study of families who were oversampled from low-income and African American families at the birth of a new child (N = 1,292). Ninety-nine percent (N = 1,036) of children who participated in the age 5 home visit completed 1 or more (M = 5.8, Mdn = 6) of the 6 EF tasks. Results indicated that tasks worked equally well for children residing in low-income and not low-income homes, that task scores were most informative about the ability level of children in the low-average range, that performance on EF tasks was best characterized by a single factor, and that individual differences on the EF battery were strongly related to a latent variable measuring overall academic achievement, as well as to individual standardized tests that measured phonological awareness, letter-word identification, and early math skills.