The causal relationship between interest rates and inflation is highly debated in the literature. The Fisher approach argues that inflation expectations determine the nominal interest rate, whereas the Neo-Fisher approach contends that the level of the interest rate is a key determinant of inflation. This study aims to analyze the direction of the relationship between interest rates and inflation in Türkiye. In doing so, it seeks to contribute to the ongoing literature by offering evidence based on the Turkish experience regarding the interaction between inflation and interest rates. Using quarterly data for the period 2003–2024, the relationship between interest rates and inflation is examined through ARDL analysis. Thus, within the framework of the ARDL model, the validity of both the Fisher and Neo-Fisher hypotheses has been evaluated. The ARDL bounds test results indicate the existence of a long-run relationship between interest rates and inflation. The long-run coefficients and error-correction dynamics generally reveal that the classical Fisher effect is more dominant in Türkiye. The limited long-run evidence for the Neo-Fisher effect suggests that the level of the interest rate does not exert a persistent influence on inflation in Türkiye. This empirical finding indicates that nominal interest rates cannot be sustainably lowered without achieving a permanent decline in inflation. Therefore, monetary policy should shift its focus from the interest rate level to inflation dynamics and expectations management