This chapter examines the legitimation efforts of the Shanghai Cooperation Organisation (SCO). It shows that despite its very weak institutions and close resemblance to ‘enterprise association’, legitimation offers an important perspective for understanding the roles the SCO plays for its member states. The chapter argues that on the one hand, the SCO legitimates itself with regards to its members by addressing regional functional cooperation problems, by providing an institutionalised framework for managing relations between the region’s hegemonic powers (China and Russia), and by occupying political space in the region that could otherwise be entered by more liberal organisations and states. On the other hand, the SCO also legitimises non-liberal norms (and exceptions to otherwise applicable international norms) that are advanced by its members, especially China and Russia, and provides states that want to escape the scrutiny of Western-dominated international organisations with an institutional alternative and an attractive alternative model.