Investment activity is essential for economic growth, innovation, and competitiveness. Understanding the factors that influence investment decisions is crucial for policymakers and business leaders. This study investigates the impact of inflation rates and interest rates on investment activity in Uzbekistan’s national economy. We utilized a dataset containing monthly economic indicators from the State Statistics Agency and the Central Bank of Uzbekistan, covering the period from January 2020 to December 2023. Employing econometric models and structural equation modeling (SEM), we analyzed the relationship between investment levels, inflation rates, and average interest rates. The econometric model was validated using various statistical tests, including the Durbin-Watson and Shapiro-Wilk tests. Our findings reveal a significant negative relationship between inflation rates and investment volumes, with a regression coefficient of −0.74 (p < 0.01). Similarly, average interest rates negatively impact investment volumes, with a coefficient of −0.54 (p < 0.05). The SEM analysis corroborated these results, showing a consistent negative impact of inflation and interest rates on investment activity. The results underscore the importance of maintaining stable macroeconomic conditions to encourage investment. High inflation and interest rates deter fixed investment. This study emphasizes the need for effective monetary policy to create a favorable investment environment. This research provides empirical evidence on the adverse effects of inflation and interest rates on investment performance. Policymakers should prioritize stabilizing these macroeconomic variables to stimulate investment and economic growth. Future research could extend this analysis to include other macroeconomic factors and different geographic regions.