In the global competitive environment, the gains or losses resulting from the performance displayed by businesses cannot be accurately reflected solely by financial data. This can affect the decisions of current or potential investors, lenders, society, and all stakeholders. In order to accurately reflect business performance, it is necessary to explain it with all tangible and intangible assets. This would help to add corporate governance to businesses and gain a competitive advantage, as well as being beneficial to society in terms of transparency. Intellectual capital encompasses all intangible assets that do not appear on a company's balance sheet, but are essential for the company to operate. The aim of this study is to examine the relationship between intellectual capital and company performance. The data of 53 businesses within the BIST Sustainability Index in 2021 were examined, and Ante Pulic's Intellectual Value-Added Coefficient method was used to measure intellectual capital. Profitability, efficiency, and market value were used as performance metrics for the study. The results of this study will be interpreted based on the correlations and regression analysis that were observed.