This article criticises the conventional social upgrading concept in global value chain (GVC) research based on an inadequate consideration of how power relations affect workers’ conditions. The authors present a re-conceptualisation based on a critical understanding of worker power that is conditioned by different relationships on a vertical axis and local capital-labour and state-society relations on a horizontal axis of GVCs. They also call for an analysis of the intersectionality of worker identities in power relations and the exercise of power. Hence, worker power, discussed in this article as structural and associational power, is exercised at the cross-section of the vertical and horizontal axes and embedded in state-society relations and multiple identities of workers. An exemplary analysis of the clothing sector in Cambodia shows how the re-conceptualisation can be useful to assess social up- and downgrading processes.