This article is based on the conception of language teaching as a liberatory practice. Drawing on some principles of critical pedagogy (Ellsworth, 1992; Freire, 2005; hooks, 1994; Norton & Toohey, 2004), critical applied linguistics (Pennycook, 1990, 2001), critical language teaching (Ferreira, 2006; Pennycook, 1999), and critical language teacher education (Hawkins & Norton, 2009), the authors developed a case study in a language center of a federal university in the state of Goias, Brazil, in which they analyzed the challenges of teaching English through critical themes based on students' perception and on collaborative reflections between the teacher and his collaborator. They found that, in general, students were pleased with their development concerning language and critical thinking as a result of engagement in the dialogic process established in class for 4 months. However, the research also implies that language teachers, when adopting critical teaching, should learn how to engage fully with students' positions and academic voices, choice and length of themes, and the conception of language as a social practice. (Contains 2 tables and 5 footnotes.)