This study examined how well monetary policy tools worked in helping Nigeria to achieving its inflation targets from 1981-2023. To achieve this, the study collected data on inflation rate, monetary policy rate, broad money supply, exchange rate, lending interest rate and real gross domestic product from reports by Nigeria's central bank and the World Bank. An Autoregressive Distributed Lag - ARDL technique was used as the main tool of analysis. The findings from this method showed that there is a long-term relationship between the different factors studied. In the long run, the monetary policy rate, money supply, and lending interest rate had a negative but not strong connection with inflation rate. On the other hand, exchange rate and real gross domestic product showed a positive but not strong relationship with inflation rate. In the short term, the monetary policy rate, money supply, and exchange rates had a positive and strong link with inflation. Meanwhile, lending interest rate and real gross domestic product had a negative and strong link with inflation rate. Based on the findings, this study concluded that in Nigeria, inflation is highly sensitive to monetary expansion, interest rate adjustments, and exchange rate movements, but the effects are inflation-enhancing rather than stabilizing highlighting the need for a more coordinated and structurally grounded monetary policy framework rather than relying on MPR adjustments alone. From a policy standpoint, the study recommended amongst others that broad money supply growth must be carefully controlled to avoid liquidity-driven inflation. The central bank should continue to use lending rate adjustments as an effective short-run inflation control tool, but with caution to avoid credit starvation in the economy. Inflation targeting should be complemented with policies that expand real output (RGDP), since growth itself helps reduce inflationary pressures.