Case studies are one of the best-known teaching methods used in business schools. How did the case study method, first popularized by the Harvard Business School, come to be adopted by the business world in France? Some research of its spread during the interwar years has been conducted, but little is known about later periods. This article focuses on a missing link in the method’s history, involving a business school in the north of France, the École d’Administration des Affaires de Lille, in the early 1950s. It examines the spread of the case study method in three parts. First, it explores the context of the school’s founding and the factors contributing to the spread of the method. Next, it looks at the school’s programs and teaching methods. Lastly, it focuses on one example to show the role of the economic and religious context in the method’s success.