In 2011, five German beech forest areas were declared to be part of the World Heritage property “Primeval Beech Forests of the Carpathians and the Ancient Beech Forests of Germany.” Thus, they now share the same status as Australia’s Great Barrier Reef and East Africa’s Serengeti. This paper analyzes the science–policy interface behind the nomination and inscription process in the multi-level governance setting of the World Heritage Convention. Using the Research–Integration–Utilization (RIU) model of scientific knowledge transfer, we identify and analyze different actors’ roles in the spheres of Research, Integration and Utilization across different governance levels, from the German federal states to the World Heritage Committee. In addition, the RIU model serves to normatively examine the process and determine quality criteria that were useful for a successful inscription as World Heritage. The paper highlights the opportunities of using scientific knowledge in the multi-level governance of international conventions.