This study investigates the challenges sixteen non-native preservice ESL teachers in a Bachelor of Education (English Language) (BEdEL) programme from Hong Kong experienced in an eight-week teaching practicum. Qualitative data from semi-structured interviews and reflective journals were collected from all 16 participants to obtain a detailed description of the participants’ perceptions of their field-based practicum experiences. Results indicate that the preserviece teachers’ practicum was characterized by a reality shock due to difficulties in experimenting with pedagogical practices they were taught in the BEdEL programme, and a lack of sense of control in class. This reality shock could destabilize the already anxious student teachers and have adverse effects well beyond the eight-week teaching practicum. Inadequacy in English language competence also appeared to affect not only these student teachers’ teaching performance but also how they established and maintained their teacher role and relationship with their students. Implications of the results for strengthening current ESL teacher preparation programmes in non-native English speaking contexts are discussed. Copyright © 2013 Graylands Teachers College.