Despite the abundance of research on the potential of lesson study for promoting teachers' professional growth through practice and collaboration, little is known on how language teachers perceive this strategy for their computer assisted language learning (CALL) professional development. In an attempt to contribute to this research base, this article shares the findings of a case study on five English as a foreign language (EFL) teachers' perception of the impact of lesson study on their professional growth. Participants' responses to interview questions along with their reflection journals were analyzed adopting constant comparison method. The findings indicated that participants appreciated the teaching practice and peer observation for promoting their knowledge of technology, technological pedagogical knowledge, knowledge of technological glitches, and their confidence in teaching with technology. It was also observed that teachers preferred peer critique to positive feedback for improving the quality of their lesson plans. The results could provide CALL teacher educators and program designers insights into benefits and challenges of engaging EFL teachers in lesson study during CALL teacher education.