In criminal matters, intentionality constitutes one of the central criteria in the work of legal characterization. This chapter shows how magistrates, and more particularly public prosecutors, practically organize their activity around the establishment of this component of the crime. I shall start by giving a summary of the literature in legal theory pertaining to this question. The essentially semantic nature of these approaches will be noted as they attempt to comprehend intention as a philosophical notion independent of the institutional context of its use. In a second step, I shall propose a praxeological approach in which intentionality is viewed as the result of interactions integrated in the judicial institutional context, which obliges professional actors to orient themselves toward the production of a legally relevant decision. This leads us, in conclusion, to observe that lay actors adjust themselves to this constraining institutional context, influenced by the inductive reasoning of professionals and by their own anticipation of the means which enable them to obtain from the place and the persons with whom they are confronted the most favourable, or the least damaging, solution for themselves, or simply the solution best adapted to the routine accomplishment of their work.