Storytelling as a formal educational device arguably entered the didactic scene about 100 years ago with case study teaching at Harvard (Herreid 1994). There in the law and business schools, instructors and students analyzed realistic stories as exemplars of good and bad practice. Today, however, storytelling does not have to be limited to the traditional discussion formula advocated in these schools. This chapter describes various types of case study methods, reviews their virtues and weaknesses, and discusses the impact of case-based instruction in science education.