In the last 15 years, the link between identity and regional institutions has received considerable academic attention, especially from EU scholars. Mostly, their focus has been on the ways in which European institutions affect, constrain or constitute (or otherwise) states’ and individual actors’ behavior and identities. By contrast, IR has been strikingly silent on the question of the identity of regional institutions. However, studying an institution’s identity can highlight important aspects of its ‘quality of life’; not least its ability to interact with other international actors and with its own constituent parts. This paper argues that a clear identity is necessary for the organization to project itself internally, internationally, and temporally. The question of institutional identity—and the risks of failing to construct one—is explored by looking at the case of Mercosur, an association which, the paper argues, suffers from identity crises in its three main identity dimension; political, economic and external.