Converging evidence suggests that homeless and highly mobile children in the United States often begin school with limited school readiness skills, such as academic knowledge and socioemotional competencies. Research also indicates that executive function (EF) is foundational to learning and social skills in young children, including those experiencing homelessness. These findings suggest that school readiness could be improved by targeting EF skills. The current pilot study examined implementation and promise of Ready? Set. Go! (RSG) – a brief intervention developed to improve EF among high-risk preschoolers through teacher training, EF-focused activities, individualized child coaching, and parent education. Participants were 75 preschoolers from an emergency homeless shelter and community organization serving similarly disadvantaged families. Results indicated RSG was appealing to parents and teachers and could be implemented with high fidelity. Children who received RSG showed significantly greater improvements in their EF skills than comparison children 1 month after the intervention ended. (author abstract)