The field of language instruction is crucial in Canada, given the number of newcomers seeking to improve their English (or French) language skills after arrival. For those who plan to enter post-secondary education but do not meet required language proficiency scores, English for Academic Purposes (EAP) programs provide opportunities to strengthen linguistic and academic skills. These inarguably pragmatic goals are often unquestioned, yet EAP instruction is an ideological undertaking with social, economic, and political consequences. This qualitative study investigates language ideologies - rationalizations and justifications for language use and form - through interviews with EAP writing instructors. As participants discussed the material they taught, the language skills students developed, and the consequences of studying EAP writing, ideologies regarding what forms of language should be taught, the purposes of academic writing (instruction), and the social and political dimensions of language were (re)produced and resisted. Formative influences on these ideologies included education, upbringing, and personal language learning experiences. Developing a critical awareness of the understandings of language that inform teaching and learning can make more transparent the linguistic and social discourses that circulate within and beyond EAP writing classrooms and help instructors, students, and other EAP community members (re)produce or resist them strategically.