Despite the importance of teacher educators in influencing the quality of teacher education and by extension, the teacher quality, teacher educator preparation and professional development has received little attention from researchers and its pedagogical knowledge domain is often generalized from that of teachers. This study therefore explored the knowledge development of prospective teacher educators through creating multimedia case studies of practice. The study was based on the analysis of data collected previously through a teacher development experiment with eighteen prospective teacher educators during a two-semester course for doctoral students in several teacher education programs. I adopted Cochran-Smith and Lytle's theorizing about relationships of knowledge and practice that makes distinctions among three prominent conceptions of teacher learning -- Knowledge-for-practice, knowledge-in-practice, and knowledge-of-practice -- to describe essential knowledge for teacher educators. I used the constructivist grounded theory approach as a data analysis strategy to explore the participants' experience in creating multimedia case studies to develop theories that were useful to understanding their knowledge development. The results revealed that through the creation of multimedia case studies of practice, the prospective teacher educators developed greater appreciation of the complexity of teaching and learning, appreciated the importance of reflection as a task of teaching and learning, got the opportunities to think in new ways about their own learning and developed better understanding of linking theory and practice. The pedagogical implications of these findings generally indicate that prospective teacher educators need professional development opportunities that would lead them to confront and break their previously held conceptions about teaching and learning while embracing research-based developments in education. [The dissertation citations contained here are published with the permission of ProQuest LLC. Further reproduction is prohibited without permission. Copies of dissertations may be obtained by Telephone (800) 1-800-521-0600. Web page: http://www.proquest.com.bibliotheek.ehb.be/en-US/products/dissertations/individuals.shtml.]