Advocating the case study method as a valuable learning tool in the study of interpersonal relationships, this paper discusses how case studies can be used as the major research project in interpersonal communication classrooms, requiring students to study the communication of an ongoing relationship for the course of the semester. Following a brief explanation of the case study method, the paper presents a detailed explanation of the case study research project, including a description of it, a discussion of research design, an outline of data collection techniques (including observations, interviews, surveys, and artifacts), a description of the final product, and project ground rules. The paper further discusses the advantages and disadvantages of case studies, and concludes that the case study method is an extremely flexible method which allows for a variety of data sources, and which provides detailed information that enhances the understanding of the relationship under study. (SR)