This narrative case study examined how a Hispanic language teacher invested agency while developing professional identities in different contexts. A recursive analysis of interviews and journal entries indicated that the participant's English language learning experience, the discrimination and marginalization in the work environments, and the knowledge gained through graduate studies all shaped her agency and professional identities development. The findings highlight the complex links among and significant roles of ethnic and racial background, past experience, and power differentials in shaping the dynamic nature of teacher agency and identities.