The health promoting school concept is now a well‐established framework for the development of health promotion initiatives in schools. Increasingly, attention has focused on the evaluation of school‐based health promotion and debate continues over appropriate evaluation designs for the school setting. The authors argue that the case study design provides a useful approach because of its ability to explore the real‐life complexities of social contexts using a combination of quantitative and qualitative methods, with a strong emphasis on process as well as outcome measures. The current ENHPS project in Scotland uses a multiple‐case study design to evaluate healthy eating initiatives in four schools, based on the principles of the health promoting school. Provides a description of the project and highlights the advantages of case study methodology in addressing key issues around effectiveness of school‐based health promotion based on the health promoting school concept.