In the paper we estimate a simple New Keynesian Dynamic Stochastic General Equilibrium NK DSGE model on the basis of Polish macro data from the period 2000-2019. The model is specified similarly to Galí (2008) with the use of the Bayesian approach. The NK DSGE model combines the advantages of both structural models and time-series models and, therefore, shows a significant degree of alignment with empirical data. The Bayesian estimation is based on the prior distribution of the model input parameters, which are later compared with the posteriors. The results obtained allow for assessing the persistence of responses to technological, inflationary and monetary policy shocks. On the basis of the NK DSGE model, we formulate a perception of macroeconomic interactions, e.g. nominal interest rates’ association with inflation and the output gap. In other words, the NK DSGE model provides a better understanding of the relationship between interest rates, inflation and the output gap. This in turn makes it easier to understand the monetary policy response function.