Corporate governance mechanisms Bank performance Saudi banking sector ROA ROE Board independence Ownership of the largest Shareholder Foreign ownership Audit committee size.This study investigates the effect of Corporate Governance Mechanisms on bank performance, using a sample of nine Saudi banks during the period 2011-2016. The study employed six corporate governance mechanisms to examine their effect on two performance measures; ROA and ROE. In addition, the study used three control variables to separate the effect of the corporate governance variables on bank performance. Using panel data regression, the results indicated that board independence and the ownership of the largest three shareholders were the only corporate governance mechanisms that have a negative and significant effect on ROA. Board independence and the ownership of the largest three shareholders had a negative and significant effect or ROE, while the ownership of the largest shareholder and the size of audit committee had a positive and significant impact on ROE.Contribution/ Originality: This study is one of very few studies which have investigated the effect of corporate governance on the performance of Saudi banks. Most previous studies have been done before issuing the last principles of corporate governance in 2014. INTRODUCTIONCorporate governance has attracted a great deal of debate among researchers during the last three decades.Corporate governance can be defined as the system, structure, and processes through which businesses are directed and controlled (Lee, 2008). Many previous researchers (such as Brick et al. (2005); Kajola (2008); Jackling and Johl (2009); Black and Kim (2012); Zaman R. (2015); Taguchi and Wanasilp (2018)) found that a good corporate governance enhances profitability and increases firm's performance.According to Todorovic (2013) good corporate governance can prevent corporate scandals and fraud, reduce its civil and criminal liability, enhance its image and reputation and increase the confidence of stakeholders. Moreover, Narwal and Jindal (2015) indicated that for developing economies, good corporate governance is an essential tool for globalization of business organizations.