This study aims to examine the connection between corporate governance mechanisms and non-performing loans (NPLs) using agency theory. In addition, the study examines the moderating effect of concentrated ownership (CO) between NPLs and financial distress. The study adopts a sample of 42 Iraqi banks from 2017–2021 with 210 observations. Panel estimation utilised a regression estimator to test the research hypotheses of the study. Three regression models were used to test the hypotheses after obtaining the appropriate model. Our findings showed that non-executive directors, board financial experience, and risk management committee affected NPLs negatively. At the same time, the audit committee was an insignificant effect on NPLs. Moreover, concentrated ownership as moderating interacts with the relationship between corporate governance factors and NPLs. This study enhances the knowledge and implications of the theory used for corporate governance dimensions. It provides feedback and a map through which Iraqi regulators and decision-makers can improve the effectiveness of corporate governance practices in relation to NPLs control, which should enable Iraqi regulators and policymakers to improve the corporate governance system, especially since corporate governance is a new issue in Iraq. The study also offers the researchers, academics, regulators, and policymakers' proof of the detrimental impact of CO on NPLs since this study provided an original contribution by using CO in this position. Therefore, evaluating CO as a moderating function provides several literary and theoretical insights that can be a focusing area of future studies.