The aim of this study was to determine the major categories of English language teacher educators' pedagogical knowledge base. To this end, semi-structured interviews were conducted with 5 teachers, teacher educators, and university professors (15 participants in total). The results of data analysis indicated that teacher educators' pedagogical knowledge encompasses eight macro categories; namely, knowledge of language and related disciplines, knowledge of ELT theories, skills, and techniques, knowledge of context and social relations, knowledge of class, time, and learning management, knowledge of research and professional development, knowledge of practicum, knowledge of teachers and their assessment, and knowledge of reflective and critical teaching. Among these categories, the first four ones are shared by language teachers, while the rest belong to the domain of teacher educators. The findings also revealed no significant statistical difference among the categories proposed by the three groups of the participants. The results are discussed and suggestions are provided for future research. (Contains 2 tables and 1 figure.)