Because the period of transition at the beginning of kindergarten can potentially impact an individual’s overall development, preventive intervention at the transition to kindergarten could have long-lasting and widespread impacts on the lives of children and their families. In this chapter, we present the Kids in Transition to School (KITS) Program, an evidence-based preventive intervention designed to capitalize on the period of the transition into kindergarten in preparing high-risk children for school. KITS features components for both children and parents. The program has specific foci on developing children’s early academic, social, and self-regulation skills and increasing parents’ school engagement and the use of positive parenting practices. KITS teachers and parent group facilitators are trained in evidence-based techniques important for teaching individuals new skills with a particular focus on teaching social–emotional skills. KITS has been tested in three randomized clinical trials. Results have demonstrated that the program positively affects children’s academic and self-regulation skills as well as parents’ use of consistent parenting techniques and school involvement. Effects of KITS have also been demonstrated at a neurobiological level. Finally, the effects of KITS appear to persist at least until the third grade, 4 years after the completion of the program.