Since children and adolescents spend a large amount of time each day at school and consume a substantial portion of their daily food intake there, it is critical to assess food and beverage availability and what youth are eating in this setting. The national School Nutrition Dietary Assessment (SNDA) studies provide a comprehensive picture of the food and nutrient content of school meals, provide national benchmarks for determining how well school meals meet nutrition-related standards, and examine trends over time. SNDA-III, conducted in 2004-2005, provides the most comprehensive information about school meal programs as well as competitive foods and the overall school food environment for elementary, middle, and high schools. This editorial reviews SNDA-III findings and policy implications for improving school foods, food environments, and diet and body weight among U.S. children and adolescents.