This paper presents the methodology, programme logic and conceptual framework that drove the evaluation of the Fifth Phase of the WHO European Healthy Cities Network. Towards the end of the phase, 99 cities were designated progressively through the life of the phase (2009-14). The paper establishes the values, systems and aspirations that these cities sign up for, as foundations for the selection of methodology. We assert that a realist synthesis methodology, driven by a wide range of qualitative and quantitative methods, is the most appropriate perspective to address the wide geopolitical, demographic, population and health diversities of these cities. The paper outlines the rationale for a structured multiple case study approach, the deployment of a comprehensive questionnaire, data mining through existing databases including Eurostat and analysis of management information generation tools used throughout the period. Response rates were considered extremely high for this type of research. Non-response analyses are described, which show that data are representative for cities across the spectrum of diversity. This paper provides a foundation for further analysis on specific areas of interest presented in this supplement.
