The present study investigates the interdependence between Ukraine’s gross domestic product (GDP), capital investments, and industrial production through the construction of a simultaneous equation model. The analysis, which is based on statistical data from 2000 to 2019, identifies the key factors influencing economic dynamics. These factors include household income, export volume, unemployment rate, and gross external debt. The model comprises three equations, each of which is statistically significant. These equations demonstrate strong mutual relationships among the variables. The findings of the study demonstrate that investment exerts a twofold effect on economic growth. Firstly, it has been shown to stimulate GDP growth, a phenomenon that is well illustrated by the investment multiplier theory. Secondly, it has been demonstrated that GDP growth positively influences investment activity. The model demonstrates a high level of explanatory power and provides a reliable basis for forecasting and for policy decision-making regarding capital investment and industrial development strategies in Ukraine.