The case study approach is a valuable method for in-depth, multi-faceted exploration of complex issues in their real-life settings. This paper reflects on the different types of case study designs, their specific research questions, data sources, and the advantages and disadvantages of using this method. The authors provide insights into when to consider employing case studies, discuss key methodological considerations, and offer practical guidance for designing and appraising proposals for conducting case study research. They also include a checklist to help readers assess the quality of case study reports. The paper concludes by emphasizing the importance of theory in underpinning case studies and acknowledges the different epistemological approaches used in case study research. Examples from various health-related case studies are provided to illustrate the application of these methods.The case study approach is a valuable method for in-depth, multi-faceted exploration of complex issues in their real-life settings. This paper reflects on the different types of case study designs, their specific research questions, data sources, and the advantages and disadvantages of using this method. The authors provide insights into when to consider employing case studies, discuss key methodological considerations, and offer practical guidance for designing and appraising proposals for conducting case study research. They also include a checklist to help readers assess the quality of case study reports. The paper concludes by emphasizing the importance of theory in underpinning case studies and acknowledges the different epistemological approaches used in case study research. Examples from various health-related case studies are provided to illustrate the application of these methods.