The purpose of the study was to explore the role of journal as a way to encourage pre-service teachers to reflect on their own learning experiences and to determine the extent of reflection through journal writing. Journals were kept by pre-service English teachers during a teacher preparation course where the focus was on the understanding of second language acquisition. Sixteen participants were juniors in an undergraduate teacher development program in a university in Korea. The journal entries the trainees kept were analyzed through content analysis method in relation to the dual role as learners and prospective teachers. Within this research framework, it was found that the pre-service English teachers reflected internally on their English learning experiences and could connect the concepts and abstract ideas to their personal experience of learning English. Also, pre-service teachers were able to display their reflective capabilities through the exercise of journal writing in spite of their limited L2 writing skills. From the findings it is suggested that journals can be used as a valuable tool for the teachers-in-preparation, both in developing reflective teachers and in generating powerful insights which later would influence their own classroom behavior and motivation as a teacher.