Discourse theories and methods have been a staple in social and political studies for a long time. However, I claim that even in the most advanced accounts of post-structuralist ontology and epistemology materiality is under-theorized, weakening discursive approaches and leading to a sense that social and material/natural worlds are in some significant way separate and operate differently. Karen Barad’s theory of agential realism, which builds on quantum physics, is deployed to show that this need not be the case. The paper explores the question of materiality and matter and its relation to discourse, by bringing Barad’s insight and post-structuralist discourse theory together. This exercise contributes to the discussion on feminist new materialism, the question of agency and structure and to the onto-epistemology of social sciences.