The Effect of Companies' Internal Control Structures on Their Financial Performance: An Application on BIST-30

Purpose: The aim of this study was to investigate the effect of internal control structures on the financial performance of firms included in the BIST-30 Index. Design/Methodology: The data of the firms for the period 2018-2022 were used annually. Return On Equity and Market value to book value were used in the study to represent profitability as dependent variables. The independent variables were the number of audit committee members, the number of internal control reports, the number of audit committee meetings, the number of audit committee reports, and the rate of graduates in the audit board. GMM which is a dynamic panel data analysis technique and Driscoll Kray Regression were used as the method. Findings: As a result of the findings, it is seen that the ratio of postgraduates on the audit committee, the number of audit committee members and the number of audit committee reports may have an effect on both ROA and PBRD, while the audit firm being a large firm may have an effect only on PBRD. Limitations: The reason is that the study was applied only to Türkiye and no country comparison was made. Originality/Value: There are a limited number of studies examining the impact of companies' internal control structures on their financial performance. This study is original in terms of both variables and method.