United States interest in the potential early childhood programs have for improving outcomes for children is shared by policymakers and researchers in many other nations. Throughout the world, enrollments in preschool and child care programs are rising. This article reviews international research documenting how participation in early childhood programs influenced children's later development and success in school. Studies conducted in 13 nations (Australia, Canada, Colombia, France, Germany, India, Ireland, Japan, Singapore, South Korea, Sweden, Turkey, and the United Kingdom) are included, along with key features of each nation's provision of early childhood programs. The article summarizes conclusions that are supported by research in various countries, indicating that participation in preschool promotes cognitive development and school success, although the specific type of program attended matters little. Preschool experience helps low-income children narrow, but not close, the achievement gap separating them from more advantaged children. International evidence also suggests that maternal employment and reliance on child care do not harm children and may yield benefits if the child care is of good quality. The author draws insights from the experience of other nations concerning such issues as defining quality, the effectiveness of early childhood programs in redressing social and economic inequities, and understanding how research can influence policy.