This study investigates the impact of corporate ownership structure and board size on earnings management for asample of Turkish firms registered on the Istanbul Stock Exchange (ISE) for the period of 2009 to 2012. The corporate ownership structure is measured with two variables: managerial ownership and institutional ownership. The board size can be defined as the number of members in the board. This study also uses three controlled variables: return on assets, size of the firm and financial leverage. The adjusted Jones Model (Dechow, Sloanand Sweeney, 1995) and the multivariate regression technique are utilized to examine the effect of corporate ownership structure and board size on earnings management. The results consistent with the previous studies show that the institutional ownership and the board size have a negative significant effect on the earnings management while the effect of the managerial ownership on the earnings management has positively statistically significant. The findings also reveal that the return on assets has a positively statistically significant effect on earnings management. However, the impact of the financial leverage on earnings management isnegatively statistically significant.