The National Strategy for Higher Education in Ireland (2011) recommends that academics should have access to professional development opportunities to develop their knowledge of teaching, as well as their disciplinary knowledge. In the former respect, the professional development needs of teacher educators differ from those of academics in other university disciplines. Teacher educators enter universities after careers as school teachers, a mid career transition from teacher to teacher educator which brings ensuing changes in professional identity and a need to acquire new professional knowledge and understanding. Because their backgrounds are in school teaching and learning, beginning teacher educators have high levels of understanding and competence in pedagogy. But they need not only to be able to teach, but also to teach teaching (Loughran, 2010). Professional development needs therefore include opportunities to transmute their knowledge-in-action (Schön, 1983) into knowledge-of-practice (Cochran-Smith and Lytle, 1999), the latter being conceptualized as knowledge that integrates both theoretical constructs and practical knowledge. Using data from a series of case studies of teacher educators on pre-service programmes in an Irish University, this paper describes and conceptualizes the strategies employed by teacher educators in order to transmute knowledge-in-action and to subsequently teach student teachers.