The paper presents a version of the P* model of inflation dynamics for a small open economy and applies it to the Czech economy time series from the period of 1991-1999. The paper is organised as follows. Section 2 presents a brief discussion of the monetary policy indicators issue. Section 3 describes the logics of the P* model. Section 4 explains the extension of the basic model to the case of a small open economy. Section 5 applies the model to the Czech economy data and presents the estimates of the Czech inflation dynamics determination. The results of the estimates suggest that the dynamics of the Czech inflation evolves in line with a P* model logic: the inflation in the current period changes to close the price gap, i.e. the gap between actual and equilibrium price level. The foreign component of the price gap seems to be more important than domestic component which supports the hypothesis that the equilibrium price level in the Czech Republic is to a large extent determined by the monetary policy in the EU via the explicit or implicit peg of the Czech currency exchange rate to EUR. The overall results show that the inflation in the Czech Republic is primarily a monetary phenomenon.