This paper analyses the degree of European Union (EU) actorness within the Group of Eight (G8). Drawing on the work of Jupille and Caporaso, actorness is probed along the criteria of ‘recognition’, ‘authority’, ‘autonomy’ and ‘cohesion’. We argue that the vague and informal nature of the G8 is conducive to EU participation in the summit. The system of EU representation within the G8 can be seen as a case of constructed ambiguity because the ambiguity that is inherent in the EU’s participation has been institutionalized within the G8. When assessing the above criteria, actorness of the EU as a whole remains questionable. However, recognition, authority, autonomy and most of all cohesion differ considerably per context. We suggest that the ‘independence’ aspect of ‘autonomy’ constitutes a weakness in the conceptuali-sation of actorness and may better be replaced by ‘proactivity’. Finally, on the basis of our findings it can be tentatively hypothesised that a number of factors condition EU actorness in the G8, including the degree of integration at EU level, the degree of politicisation and whether or not an EU member state is acting as G8 host.