In this paper we summarize the results of a broad exploratory empirical analysis where we relate the level of financial development with the effectiveness of monetary policy. The analysis is based on a panel of countries for which we calculate measures both of financial development and of monetary policy effectiveness. We look for statistically significant relationships between the indicators of financial development, the effectiveness coefficients, and other macroeconomic characteristics by estimating dynamic panels and performing a cluster analysis. We present our results in the form of a list of stylized facts that we consider deserve further attention. © 2010 Blackwell Publishing Ltd.