Becoming a teacher is not developing an identity, but is developing identity as a continuous process of constructing and deconstructing understandings within the complexities of social practice, beliefs, experiences, and social norms. I take up this stance on identity as articulated in Judith Butler's (1999) work with gender identity and examine one elementary teacher candidate's discursive participation in a seminar on critical self-reflection and mathematics teaching. Analysis presents the personal tensions and complex positioning of teacher candidates and mathematics teacher educators. A discussion of the emergent dilemmas of facilitating identity work in mathematics teacher education and further questions are shared.