This study explores the mechanical properties of high-strength concrete incorporating Metakaolin (MK) as a partial substitution of cement under exposure to elevated temperatures. Metakaolin, a highly reactive pozzolanic material, is known to improves the durability and strength characteristics of concrete. In this experimental investigation, concrete mixtures were prepared with varying levels of metakaolin replacement (0%, 2%, 4% and 6% by weight of cement) and subjected to 500 ℃ and 700 ℃ for a specified duration. The main purpose of this study was to assess the impact of these elevated temperatures on key mechanical characteristics. The results provide insights into the performance of metakaolin-enhanced HSC under high-temperature conditions, offering valuable information for optimizing concrete mix designs in applications where thermal resistance is critical. This study adds to the increasing material of research on the application of additional cementitious substances to improve the mechanical and thermal properties of high-strength concrete.