As part of the recent rethinking of green politics, the construction of a green democracy has been subjected to increasing scrutiny. There is a growing consensus around deliberative democracy as the preferred model for the realisation of the green programme. As a result several arguments emerge when deliberative principles and procedures are to be justified from a green standpoint. This paper offers a critical assessment of the green case for deliberative democracy, showing that deliberation is being asked to deliver more than it is able to. However, it is suggested that the connection between sustainability, understood as a normative principle, and deliberative procedures may ultimately offer the best grounds for such a defence.