"Tools of the Mind" is an early childhood curriculum for preschool and kindergarten children, designed to foster children's executive function through development of self-regulation, working memory, and cognitive flexibility. Activities emphasize both executive functioning and academic skills. One study of "Tools of the Mind" meets the What Works Clearinghouse (WWC) evidence standards. The study included more than 200 three- to four-year-old children attending preschool in a low-income, urban school district. The WWC considers the extent of evidence for "Tools of the Mind" to be small for oral language, print knowledge, cognition, and math. No studies that meet the WWC evidence standards with or without reservations addressed phonological processing or early reading/writing. Study Characteristics data, Outcome Measures, Summarized Study Findings, Rating data, and Extent of Evidence by Domain are appended. (Contains 5 footnotes.) [The following study is reviewed in this intervention report: Barnett, W., Jung, K., Yarosz, D., Thomas, J., Hornbeck, A., Stechuk, R., & Burns, S. (2008). Educational effects of the "Tools of the Mind" curriculum: a randomized trial. "Early Childhood Research Quarterly," 23(3), 299-313.]