This is a qualitative longitudinal study of the lived experience of four mainland Chinese ESL teachers engaged in their first year of employment in Hong Kong secondary schools. Based on multiple interviews and email contact conducted over the course of one academic year, the research explores the adaptive processes these beginner ESL teachers experienced to overcome adversity and to sustain their commitments to teaching, illuminating factors which contributed to the success and failure in their first year teaching, a career phase believed to have significant implications for new teachers’ sense of efficacy and their survival in the teaching profession. Findings suggest that these teachers themselves were key actors in coping with the processes of teaching, socializing and adapting their working conditions, and in determining ultimate success or failure in their first year in school. The study highlights a need to establish supportive processes in the school environment that nurture first-year ESL teachers’ active participation in and contribution to the school community, and facilitate their learning and construction of active professional agency. The importance of university ESL teacher training course affording opportunities and experiences for preservice ESL teachers to develop the capacity to operate with professional agency in real classroom situations is also discussed.