Résumé : This paper compares the communication strategies of the Fed and the ECB and their impact on financial markets. Interest rates options were used to calculate daily probability distributions of market expectations and to examine how they are modified by central banks’ announcements. We found that Greenspan’s speeches have a stronger influence on rate levels and market uncertainty than Duisenberg’s. Moreover, market expectations most significant reaction is to economic indicators central banks mention as being important. Monetary decisions are regularly anticipated thanks to speeches and economic releases and the dominant speech themes were shown to be “monetary policy” and “domestic economy”.