The Head Start REDI Program is a research-based, developmentally-informed intervention aimed at promoting academic and social-emotional school readiness in 4-year-old children. Forty-four Head Start classrooms were randomly assigned to either the REDI intervention or "usual practice" conditions. The REDI program included brief lessons, hands-on extension activities, and specific teaching strategies linked to the promotion of social-emotional competencies and language/emergent literacy skills. Parents were provided with take-home materials to support skill development at home. Multi-method assessments of 356 children tracked their progress over the course of the one-year program. Results showed significant differences favoring children in the REDI classrooms on measures of vocabulary, emergent literacy, emotional understanding, social problem-solving, social behavior, and learning engagement. Head Start is the nation's premier federally sponsored early childhood education program, designed to reduce socio-economic disparities in school readiness. Research suggests that comprehensive, high-quality preschool programs can improve school readiness for disadvantaged children. However, findings from the Head Start Impact Study showed that while Head Start had significant benefits on some cognitive and social-emotional skills, it had no effects on oral comprehension, phonological awareness, aggressive behaviors, or social skills. The REDI program was developed in partnership with Head Start programs to target specific school readiness competencies in social-emotional development and cognitive development. It was designed to enrich and complement existing educational programming, increasing the systematic emphasis on target skills. These skills were selected because they are important predictors of grade-school adjustment and achievement. The REDI program included social-emotional skill enrichment through the Preschool PATHS Curriculum and language/emergent literacy skill enrichment through interactive reading, sound games, and print center activities. Teachers received training and mentoring to support the use of these strategies. The program also included parent take-home materials and integrated components into existing curricula. The REDI program showed significant effects on language, emergent literacy, emotional understanding, and social problem-solving skills. It also showed improvements in socially competent behavior, learning engagement, and reduced aggression. The program was effective in promoting school readiness by enhancing both social-emotional and language/emergent literacy skills. The results suggest that the REDI program can enhance the impact of Head Start programs on child school readiness.The Head Start REDI Program is a research-based, developmentally-informed intervention aimed at promoting academic and social-emotional school readiness in 4-year-old children. Forty-four Head Start classrooms were randomly assigned to either the REDI intervention or "usual practice" conditions. The REDI program included brief lessons, hands-on extension activities, and specific teaching strategies linked to the promotion of social-emotional competencies and language/emergent literacy skills. Parents were provided with take-home materials to support skill development at home. Multi-method assessments of 356 children tracked their progress over the course of the one-year program. Results showed significant differences favoring children in the REDI classrooms on measures of vocabulary, emergent literacy, emotional understanding, social problem-solving, social behavior, and learning engagement. Head Start is the nation's premier federally sponsored early childhood education program, designed to reduce socio-economic disparities in school readiness. Research suggests that comprehensive, high-quality preschool programs can improve school readiness for disadvantaged children. However, findings from the Head Start Impact Study showed that while Head Start had significant benefits on some cognitive and social-emotional skills, it had no effects on oral comprehension, phonological awareness, aggressive behaviors, or social skills. The REDI program was developed in partnership with Head Start programs to target specific school readiness competencies in social-emotional development and cognitive development. It was designed to enrich and complement existing educational programming, increasing the systematic emphasis on target skills. These skills were selected because they are important predictors of grade-school adjustment and achievement. The REDI program included social-emotional skill enrichment through the Preschool PATHS Curriculum and language/emergent literacy skill enrichment through interactive reading, sound games, and print center activities. Teachers received training and mentoring to support the use of these strategies. The program also included parent take-home materials and integrated components into existing curricula. The REDI program showed significant effects on language, emergent literacy, emotional understanding, and social problem-solving skills. It also showed improvements in socially competent behavior, learning engagement, and reduced aggression. The program was effective in promoting school readiness by enhancing both social-emotional and language/emergent literacy skills. The results suggest that the REDI program can enhance the impact of Head Start programs on child school readiness.