The Paris Agreement on climate change adopted in December 2015 reflects EU policy objectives to large extent. To find an explanation, we develop a general framework that incorporates both structural and actor-/process-related factors, paying particular attention to negotiation strategy and diplomacy. On this basis, we argue that the high level of EU goal achievement in Paris resulted from the interplay of (1) evolving international structures, (2) effective EU strategy fitting these structures and domestic politics, and (3) favourable situational circumstances. While the EU arguably pushed others to their limits, downscaled ambitions also meant that it accepted a Paris Agreement that is insufficient by itself and needs to be strengthened quickly. The application of our conceptual framework to the Paris Agreement demonstrates its added value and that it can build the basis of a fresh programme of work comparing the EU’s performance in international institutions/negotiations across time and policy fields.