Knowledge and human identity are socially constructed phenomena. Like other aspects of human identity, teacher identity is shaped through social influences. Some of the social influences that contribute to teacher identity development happen through critical incidents that teachers or teacher candidates experience. The current study, adopting a critical incident analysis perspective, attempts to ascertain the nature of the critical incidents that 49 pre-service teachers of EFL have experienced throughout their English learning process. It also tries to uncover the effects of these critical incidents on their English learning and teacher identity. The data for the research was collected using a Critical Incident Form developed by the researchers and focus group interviews. The findings indicated that pre-service ELT teachers' early learning experiences included certain critical incidents. An inductive quantitative analysis of these incidents revealed that they can be categorized into three themes: people, context, and outcome. Exploring the nature of critical incidents and their role in the construction of English language teacher identity will hopefully be a benefit to teachers and teacher educators.