In the context of literacy being understood as an evolving concept, this article argues that a particular form of literacy, pedagogical literacy, is an important cognitive tool for a developed conceptualisation of pedagogical content knowledge and that, by extension, being "pedagogically" literate is an integral feature of being a professional teacher. Pedagogical literacy is a reflexive concept in which reading and writing (through a knowledge-transforming model) about pedagogical content knowledge is the essential means through which the teacher's pedagogical reasoning develops.