The history of formal education in Iran shows that teacher training, in its contemporary meaning, started in 1918 when the first center for training male teachers (Daarolmo’ allemin) along with Daarolmo’ allemaat for female teachers was established. During the past one hundred years tremendous changes have taken place in terms of structure, curriculum, and regulations. According to the available documents 42 different training centers have existed over this period in order to provide well-trained elementary and high school teachers, counselors, and principals. Apparently with any ministerial change taking place, these teacher training centers have also changed, shut down, or consolidated. Based on these documents, the history of teacher training in Iran can be laid out in six divisions including one on the significance of teaching and teacher training, and other ones on teacher training background, the genesis of teacher training, studies and approaches, teacher training in Fundamental Reform Document of Education (FRDE), and opportunities, threats, and outlooks.