A series of corporate failures and financial crises have raised attention to organizational governance issues, especially for financial institutions. In the banking system, corporate governance further plays a unique role because of the uniqueness of the banking organizations. Therefore, this study aims to examine the effect of corporate governance disclosure on bank performance by building a corporate governance disclosure index (CGDI) for 10 Islamic banks operating in Iran, Saudi Arabia and Malaysia. The data used in this study are secondary data taken from annual reports and sourced from the official websites of each banks include Iran Exchange, Stock Market Quotes and Financial News, and Bursa Malaysia. This study uses content analysis of the annual bank report within five years (2014)(2015)(2016)(2017)(2018). The results show that Islamic banks comply with 72.4% of the attributes discussed in the CGDI. The most frequently reported and disclosed elements are board structure and audit committee. The regression results provide evidence that Islamic banks with a higher level of corporate governance disclosure reported high operating performance measured by ROA. In contrast to the expectation, the financial performance of ROE and Tobins'q are not significantly related to the disclosure of sharia bank governance.