This paper examines the current state of application of qualitative methods, namely case studies in purchasing and supply management. We argue that the case study method has much to contribute to the development of the discipline namely in terms of theory development, providing strong exemplars as well as testing theories culled from other disciplines. In examining the use of the case method in purchasing and supply management, we suggest that there is a noticeable trend away from single case designs with sparse methodological reflections to multiple case, comparative designs accompanied by the use of conventional method justifications. These developments are broadly welcomed but we identify two blind spots: (1) the relative neglect of the links between theory and method and (2) the use of inappropriate statistical criteria to justify multiple case research designs. We discuss the nature of these problems using a number of examples and formulate rules for conducting good case research.