This case is a study of the initial discovery of penicillin and how it came to be a mass-market product. The discovery of penicillin is fascinating first and foremost because of its direct, life-saving benefits and because of the context of World War II that surrounded its rise. Throughout the case, an argument is made for the importance of this invention not only for the society of the 1940s, but for our society today. Students are introduced to a handful of the individuals and institutions involved in the discovery and development of the technology, providing them with the information necessary to consider the people, institutions, and other factors that led to the drug’s success. Students consider especially the role of intellectual property during penicillin’s rise to success, as well as the cultural and legal differences between Britain and the United States related to the patenting of medical discoveries.