This study investigates the impact of a number of corporate governance mechanisms on earnings quality of listed companies on the Egyptian Exchange (EGX) as one of the emerging markets before and after issuing and implementing the Egyptian Code of corporate governance used 634 firm-year observations during the period 2003-2010. Four models of ordinary least square regressions were performed to regress six corporate governance variables namely board size, board shareholding, board independence, board leadership, audit committee and external auditor on earnings quality, which was estimated using the modified Jones (1991). We found that four independent variables (board shareholding, board independence, audit committee and external auditor) are significantly associated with the earnings quality, while the others are not. As a main finding, we found that the issuance and implementation of the Egyptian Code of corporate governance decreased the earnings management practices and improved the earnings quality of listed companies on the Egyptian Exchange.