The case study is widely used in psychoanalysis for presenting and illustrating clinical theory. It is also the standard means by which analysts-in-training demonstrate their ability both to manage cases and to convey their grasp of the case material. Most training institutes use the formal presentation of a case as a requirement for graduation. The Center for Modern Psychoanalytic Studies, New York, currently requires a single-case study as a final piece for the completion of certificate training (Meadow & Bernstein, 1999). In this paper we argue that the main purpose of the training case study is to illustrate theory systematically in clinical material and that treating the case study as an illustration addresses the main controversies over the legitimacy of the case study as a research method and, in particular, suits the needs of clinical training. In the light of this we set out a structure for the case study, giving its components and sequence and a rationale for this structure.