When the OECD decided to extend PISA to low-income nations through PISA for Development (PISA-D), it was concerned not only to adapt its instruments and surveys to ‘low-income contexts’, but also to ensure that participation in PISA-D was not just a one-off exercise. It aimed to have a long-term, meaningful effect on participating nations. It was keen that the results should be analysed and used to inform policy, and that a culture of assessment, accountability and evidence-based policy practices should be enabled and institutionalized. This was attempted through the mechanisms of the mandatory Capacity Needs Analysis and Capacity Building Plan which were integral to the PISA-D exercise. In this chapter, we focus on the ‘capacity-building’ components of PISA-D, using Cambodia as a case study. Our analysis focuses on the performative politics of mundane practices such as training programs, technical meetings and assessment protocols which can profoundly change the operations, functioning, relations, and the very identity of a nation. We take a material-semiotic, practice-based approach, and deploy Callon’s notion of ‘the third translation’ to examine the ways in which ‘capacity building’ sought to transform Cambodia in significant and enduring ways, creating new aspirations, demands and obligations.