Head Start CARES (Classroom-based Approaches and Resources for Emotion and Social skill Promotion) is a national demonstration that tests the effectiveness of three program enhancements designed to improve preschool children's social-emotional competence. The project also examines the support systems (e.g., professional development model, technical assistance, monitoring) that are needed to implement the enhancements as designed within diverse Head Start classrooms across the country. This report describes impacts of the CARES demonstration, focusing on outcomes during the spring of the preschool year in: (1) teacher practices; (2) classroom climate; (3) children’s behavior regulation, executive function, emotion knowledge, and social problem-solving skills; and (4) children’s learning behaviors and social behaviors. The report also explores possible impacts on pre-academic skills during preschool and social-emotional and academic outcomes during the Kindergarten year. All three enhancements had positive impacts on teacher practice and on children’s social-emotional outcomes during the preschool year, although in varying degrees and not necessarily in the expected ways.