Purpose - The paper aims to provide an overview of the vocabulary for materiality which is used by practice-based approaches to organizational knowing. Design/methodology/approach - The overview is theoretically generated and is based on the anthology Knowing in Organizations: A Practice-based Approach edited by Nicolini, Gherardi and Yanow. The overview is built by cross-reading the analyses in this book. The intellectual traditions which are scrutinized all agree that action is materially embedded - objects and artifacts are central to both knowing and learning. But what is their understanding of materiality? The paper explores which concepts are used, how the interaction between social and material realities is presented, and the role materiality is perceived to have in relation to action. Findings - Findings are that, within the practice-based approach, common terms for materiality are "artifact" and "object". The interaction between social and material realities is grasped as several processes: object-oriented activity, symbolization, embodiment, performance, alignment and mediation. Material artifacts both stabilize and destabilize organizational action. They may ensure coordination, communication, and control, but they may also create disturbance and conflict. Originality/value - The paper lists a range of options for conceptualizing how organizational action may be materially mediated. It points out that material entities may both stabilize and destabilize organizational action. It contributes to the further understanding of the tangible, artifactual and object-related side of organizational knowing.