The effects of the COVID-19 pandemic all over the world have manifested themselves in many ways and are still continuing.  The pandemic has also had significant effects in the world of economy and finance. Countries trying to cope with these effects use money supply and policy interest practices, which are among the monetary policy instruments. In the first part of the study, the concepts of money supply, policy interest rate and inflation were tried to be explained with their basic features. In the second part, recent important studies examining the relationship between money supply, policy interest rate and inflation and the findings obtained from these studies are included. The United States, the United Kingdom, China, the Euro Zone, Japan and India were determined as the countries examined in the study. The M1 money supply amount, policy interest rate and inflation changes in the countries discussed between 2020 and 2024 were examined graphically. In the analysis, the performance of the countries in this process was tried to be evaluated by trying to interpret the M1 money supply amount, policy interest and inflation changes and the relationships between these variables. In addition, important issues in the process of determining monetary policies are presented in the form of suggestions. It is thought that the study can contribute to understanding the concepts of money supply, policy interest and inflation and to evaluate how monetary policies implemented in the post-pandemic period are shaped and their effects.