Objective. This study aims to evaluate the impact of an intervention program, taught by trained teachers, on foods and nutrients components of the Diet Quality Index–International among children in Grades 1 to 4. Method. A total of 464 children (239 female, 6-12 years) from seven elementary Portuguese schools participated in this randomized trial. Three schools were allocated to the intervention, and four to the control group. The intervention program was based on the health promotion model and social cognitive theory. Teachers previously trained by researchers in nutrition, healthy eating, and healthy cooking implemented the intervention in the classroom from November 2008 to March 2009. Sociodemographic, anthropometric, physical activity, and dietary assessments were performed before (2007/2008) and at the end of the intervention (2009). Dietary intake was gathered by a 24-hour dietary recall and the components of Diet Quality Index–International were defined. Results. Children from the intervention schools reported a significantly higher adequacy in vegetable consumption (p = .018) and a significantly higher moderation in sodium consumption (p = .032) compared with the controllers. Conclusion. Our study provides further support for the success of intervention programs that aim to enhance children’s dietary intake. Implementing similar interventions can be promising to support vegetable consumption and moderate sodium intake.