This article analyses the impact of the exchange rate on the role of dollar and euro as international currencies. It is found that exchange rate fluctuations are a major determinant of the international role of currencies only if they reflect sizeable inflation differentials. Accordingly, major changes in the international role of dollar and euro are not to be expected given the continuation of a stability-oriented US monetary policy. However, a move towards more exchange rate flexibility in emerging market economies, reflecting the need for greater monetary policy autonomy, might lead to a relative strengthening of the international role of the euro. Copyright 2009 die Autoren Journal compilation 2009, Verein für Socialpolitik und Blackwell Publishing Ltd.