Power is involved when researchers and practitioners work together in transdisciplinary sustainability research. Among other things, this has implications regarding who gets to decide which research questions are dealt with and which partners are involved, and may impede or foster joint knowledge production.We propose empirical questions that allow for the power dynamics to be rendered visible, thus providing a first step towards tackling them. While transdisciplinary (TD) sustainability research is closely tied to ideas of societal change, critical enquiries into power dynamics both within and stemming from these practices have been scant. In this article, we operationalise theories of power for an exploration of the multiple ways in which power relations pervade interactions between researchers and practitioners in these knowledge production processes. By combining theories of power over, power to and power with, we propose a set of empirical questions to systematically study both productive and repressive forms of power. Using empirical examples, we illustrate how the proposed approach makes it possible to trace power throughout TD processes: in 1. developing the project and framing the research problem, 2. co-producing knowledge, and 3. bringing results to fruition. The power perspective proposed here can guide the thinking of those actors involved in TD processes as well as meta-analyses by third parties. An enhanced understanding of the workings of power can help improve process design and facilitate reflexive TD practice.