In this paper, we follow the econometric approach to assess relative importance of real interest rate and real exchange rate for the monetary conditions in Poland, quantified as weights for Monetary Conditions Index (MCI). We consider both single- and multiple-equation specifications proposed in the literature with an application to Poland. Although MCI is nowadays broadly considered a rather obsolete indicator in monetary policy conduct, we argue that the econometric framework used for this purpose could be a good departure point when modeling monetary adjustments in a monetary union, provided correct dynamic specification of the models.