This is a presentation related to the study of illness Scripts and medical diagnostic knowledge. The diagnosis of script questionnaire is a new tool to assess a specific dimension of clinical competence, and a model of diagnostic reasoning about medical understanding The studies contributed by several disciplines characterize the developing process of the medical knowledge by the acquisitions of units of organization of the memory that allow to build mental models specifically for the realization of certain forms or events. These cognitive units are called illness Scripts, and are used to chategorize the clinical picture studied and the guides for the take of decisions. This universal model of diagnostic reasoning known as script concordance testing is the continuing profesional development, structured from theory to practice. These aspects are discussed in the article