As conceptual and theoretical discussions on environmental valuation approaches have advanced there is growing interest in the impact that valuation has on decision making. The perceived legitimacy of the outputs of valuation studies is seen as one factor influencing their impact on policy decisions. One element of this is ensuring that participants of valuation processes see the results as legitimate and would be willing to accept decisions based on these findings. Here, we test the perceived legitimacy to participants of two approaches to deliberative monetary valuation, deliberated preferences and Deliberative Democratic Monetary Valuation, in the context of marine planning in the Clyde estuary in Scotland. We compare and contrast deliberated preference and deliberative democratic monetary valuation and track their emergence as responses to critiques of conventional stated preference approaches. We then present the results of our case study where we found that deliberative democratic monetary valuation produced valuations that were perceived as more legitimate that deliberated preference as the basis for decision making by those involved in the valuation process. </jats:p>