Despite the popularity of Model United Nations, no effort has been made to directly assess student learning since 1984. Accordingly, we developed and administered a pre- and post-conference survey to participants in the 2007 American Model United Nations (AMUN). We assessed whether participating in the simulation affected students' general knowledge of the UN; their attitudes towards the UN and the most important member states; and their understanding of diplomatic strategies. We find that first-time participants increased their general knowledge, developed a more realist orientation towards international relations, and placed more emphasis on the importance of individual agency in world affairs.