One of the characterizing features of the external policies and actions of the European Union (EU) is that they have shown a preference for interregional relations and have while actively supporting regionalization processes in Africa, Asia-Pacific, Latin America and the Caribbean. However, depending on the case and the nature of the region the EU is dealing with, these relations are assimilated with ‘pure’, ‘hybrid’ or ‘quasi-‘interregionalism. The aim of this chapter is to investigate how the EU’s policy objectives and practice of regionalism promotion intersect and interact with its trade policy objectives and practice, and how these interactions have evolved over time. The chapter adopts first a transversal approach by discussing the interregional preference in trade policy, the trade dimension of cooperation with regional organizations worldwide, and the design of preferential rules of origin. This is then combined with a study of three cases that illustrate these interactions and their evolution: EU-ACP relations, EU-CAN relations and EU-ASEAN relations. When looking closely at these cases, ‘hybrid interregionalism’ (and pragmatism) seems to be the rule, instead of ‘pure interregionalism’, and there is a tendency observable towards bilateralism. When looking at interregionalism from a trade angle, the limitations of a ‘pure’ region-to-region approach become visible. It is shown that the EU has used flexible instruments and trade-related assistance to support regional integration to follow a bilateral approach without setting aside its preference for interregionalism.