Energy consumption and economic growth are interconnected, and the relationship between them is complex and dependent on various factors. Key aspects of this relationship include: energy consumption as a driver of economic growth; technological progress and efficiency; structural changes in the economy; policies and regulations. This article examines the long-term relationship between energy consumption and real GDP for the Czech Republic and Slovakia from 2005 to 2022. Many studies have explored the linkages between energy consumption, economic growth, and energy efficiency. The aim of this contribution is to contribute to this topic by analyzing the Granger causality between the indicators. This paper focuses on the predictive power (Granger causality) rather than estimating the true causal relationship of the VAR/VECM model. The results for both countries indicate that energy consumption Granger-causes GDP. This means that energy-saving policies may slow down the pace of GDP growth. These findings are based on the analysis of Eurostat data from 2005 to 2022 for the Czech Republic and Slovakia, using the statistical software EViews 11 for calculations.