From a sociocultural perspective, identity is understood as constructed through active negotiations with others (Gee, 2006; Lantolf, 2009). Language constitutes a mediation tool used to create meanings in new social and cultural contexts as individuals become members of new communities of practice (CoP). In doing so, an ongoing process of sharing values, beliefs, and roles is enacted; and it is in this process that identity is shaped. This is especially important in the case of pre-service bilingual teachers; whose negotiated construction of a professional identity is reflected in their own teaching practices (Bustos Flores, Hernandez Sheets, & Clark, 2011). Teachers' identity will likely have an impact on their practice; it determines the beliefs they will hold regarding assumptions and perceptions about teaching, learning, students, the school, and the community. Using a multiple case study and the tools of discourse analysis (Yin, 2011; Gee, 2011a, 2011b, 2015), this research study intends to capture the personal and professional experiences of four (4) pre-service bilingual Mexican teachers, current students in a Bilingual Education/EFL program in public university in Northern Mexico exercising their practicum at the college level as they construct a teacher identity. In doing so, this study also attempts to describe the ways their identity is performed, and their perceptions regarding the impact this process has on their classroom practices. [The dissertation citations contained here are published with the permission of ProQuest LLC. Further reproduction is prohibited without permission. Copies of dissertations may be obtained by Telephone (800) 1-800-521-0600. Web page: http://bibliotheek.ehb.be:2222/en-US/products/dissertations/individuals.shtml.]