Sigmund Freud’s five long case histories have been the focus of seemingly endless fascination and criticism. This article examines how the long case-history genre developed and its impact on the professionalization of psychoanalysis. It argues that the long case histories, using a distinctive form that highlighted the peculiarities of psychoanalytic theory, served as exemplars in the discipline. In doing so, the article extends John Forrester’s work on ‘thinking in cases’ to show the practical implications of that style of reasoning. The (...) article illustrates how the form disappeared once the theoretical basis of the movement was set. The genre never became institutionalized, although the content of the five long case histories did, because of Freud’s accepted role as theoretician of psychoanalysis. (shrink)