Document Type : Original Article


Department of English Language Teaching, Ahvaz Branch, Islamic Azad University, Ahvaz, Iran



This study aimed to examine the effect of lesson study on EFL learners’ grammatical knowledge and EFL teachers’ perception toward lesson study. To collect data, 97 female students from four intact classes were selected and assigned to two groups. Two classes were assigned to the the experimental group and the other two were assigned to the control group. Three teachers participated during the lesson study project. In each cycle of lesson study, one of the teachers taught the lesson, whereas the other teachers were observing the class learning. A postlesson discussion was done among the teachers after the first lesson and necessary revisions were made according to the participants’ comments. On the other hand, the control group class was taught by one teacher. An interview was also conducted with the participated teachers at the end of the experiment. The results revealed that the lesson study had a positive effect on the participants’ grammatical knowledge. Moreover, the qualitative data analysis showed that the teachers regarded lesson study to be beneficial to help them develop professionally. The results indicate that LS can be used as a powerful tool for teacher development in both initial teacher training and in-service teacher training in EFL contexts. In addition, LS can be done in a single school to increase interaction and knowledge sharing among EFL teachers