The relationship between deliberation and sustainability is contested. A contrast can be drawn between the application of deliberation as a policy instrument and the idea of deliberative democracy as a critical social theory that challenges broader systemic injustices. While deliberation can play an important role in problem solving in the policy process, this is to miss broader emancipatory ambitions. The chapter explains the attractiveness of deliberation to those concerned with sustainability (and vice versa) and how a more instrumental reading of deliberation may undermine the capacity to embrace more inclusive and emancipatory conceptions of sustainability. Attention to the original emancipatory impulse requires a consideration of role of institutions, culture and democratic systems in our endless search for sustainability.