The question of how critical-thinking skills could be integrated into English as a Foreign Language (EFL) pedagogy has been one of the main concerns in the field of language teaching and learning as they have a great potential to increase the quality of learning and teaching. The purpose of this study was to investigate whether training based on peer feedback, including critical feedback, contributes to participants’ peer feedback and critical feedback performances. The participants, who were undergraduate English Language Teaching (ELT) students (n = 40), were exposed to an 8-week training program in which several feedback criteria, including critical ones, were introduced to them. Data obtained from the participants’ pre-test and post-test peer feedback performances and semi-structured interviews were analyzed by using SPSS and content analysis, respectively. The results revealed that the training improved performance in providing peer feedback, including critical peer feedback. Finally, learners reported satisfaction with the training program, although some challenges were encountered in the process.