Underpinned by a postmodern perspective of (teacher) identity, which characterizes it as unstable, multifaceted, unfinished, complex, dynamic, fluid, constructed in relation with others (Bauman, 2005; Bohn, 2005; Hall, 2006; Beijaard et al., 2011 among others), this qualitative research aims at exploring English language teachers' identities concerning their knowledge of slang. For this purpose, a semi-structured, audio-recorded interview was conducted with three English teachers, from the three main language institutes in Cornelio Procópio, state of Paraná. Results reveal that on the one hand, teachers consider themselves to be fluent in English and confident of their language and teaching skills; on the other, they consider their knowledge of slang to be somewhat limited. Additionally, geographical boundaries are perceived as a hindrance to address such topic in class.