‘Case study’ is a popular but also surprisingly demanding research design. In this chapter, key definitions are first discussed, then types of case study are examined, including intrinsic, instrumental and collective approaches, also single- and multiple-case design. Specific issues relating to sampling, data gathering using mixed or combined methods, validity, ethics and generalization of outcomes are explored, with discussion drawing on the author’s own research experiences. Overall, a pragmatic but analytical overview is provided of issues which a researcher is likely to meet when planning, conducting and evaluating case-study research and when deciding how its findings might inform professional and academic discourse and practice. The chapter encourages critical consideration of its adoption in education research projects.