Despite considerable attention to the unequal distribution of voting shares in international organizations, many such institutions rarely take votes and rely on consensus-based decision-making instead. This is conducive to deliberation, which holds the promise of effective negotiation outcomes, according to scholars of deliberative democracy. At the same time, powerful member-states frequently achieve their preferences through international organizations. Thus, what is the role of deliberation in decision-making of international organizations? Drawing on scholarship of international political economy and deliberative democracy, I hypothesize that deliberation is able to constrain the interests of powerful member-states at minimum, and improves governance at best. To test these conjectures empirically, I examine meetings in the governing body of the International Monetary Fund (IMF) pertaining to developing countries between 1995 and 2014. I introduce new measures of deliberative quality based on dictionary methods and supervised learning techniques. Employing regression analysis, I find that higher deliberative quality in Board meetings is associated with less conditionality in subsequent lending programs, thereby constraining the influence of powerful member-states. However, deliberative quality is not significantly related to the probability of successfully graduating from an IMF lending program. These findings have important implications for IMF governance and for international organizations more broadly. The research questions the widely used approach of deriving preferences exogenously to the decision-making process, but also shows the limitations of deliberation within organizations.