A logic that informs much contemporary governance is that policy-learning may be promoted by making successful localised experiences circulate in the guise of so-called ‘best practices’. Best practices have, therefore, also been promoted as relevant knowledge objects in the governance of urban sustainability transitions. This chapter investigates the complex politico-epistemic practices through which instances of local urban experimentation are identified and abstracted into a ‘best practice for urban sustainability transition’. It draws on in-depth insights resulting from expert interviews, participatory observation, and documentary analysis of a set of German municipalities. The analysis argues that best practice is not a transparent epistemic tool by which governance actors may effectively learn how to optimally orchestrate transition experiments, but rather a political technology that urban actors use to render particular cities, governing solutions, technologies and certain political agendas visible and attractive. The governmentality perspective being applied in this chapter, thus, contributes to revealing the underlying power–knowledge complex of best practice and helps to better understand how governing climate change operates on the ground.