Teacher professional development rests on the provision of knowledge, development of skills, and change of attitudes of teacher candidates and in-service teachers. Teachers’ professional knowledge, perceptions and teaching practice contribute greatly to student learning. This study sets out to investigate the relationships and inter-relationships among professional knowledge, academic self-concept and self-reported instructional practice which was found as a research gap in the literature. Using a sample of 92 pre-service TEFL teachers in Iran, a significant positive correlation was found between professional knowledge and academic self-concept. The findings also revealed that different domains of professional knowledge are not related to each other for TEFL. Finally, the obtained results indicated that academic self-concept affected instructional practice in total and at the level of sub-dimensions while professional knowledge had an effect on the two dimensions of instructional practice, namely cognitive activation and student learning support but not on the dimension of classroom management .
