In mathematics education, there is a growing interest in research on social aspects such as how mathematics teaching in classrooms is informed by society. Consequently, new sets of theoretical frameworks and methods have to be taken into account. In a focus group study, Critical Discourse Analysis (CDA) was used as a theoretical framework, which enabled the researcher to see how mathematics teachers resist and construct a discourse of mathematics teaching apart from the official discourse. Also shown in the study is that power relations are circulating and thereby influencing teachers in the process of planning in mathematics. In this paper, results from the study are used to emphasize CDA as useful for mathematics education researchers seeking to grasp the complex, dynamic, and emerging nature of mathematics teaching.