<p>We investigate the impact of board size and board composition on performance for a sample of 30 commercial banks from 2008 to 2012 in Turkey. We measure bank performance by two alternative measures widely used in the banking literature, i.e. operating return on assets (OROA) and return on assets (ROA). Controlling for bank size, credit risk, liquidity risk, net interest margin and non-interest income, the results of panel fixed effects regression suggest that board size has a significantly positive effect on bank’s financial performance. This means that Turkish commercial banks may improve their financial performance by increasing their board size. Our findings, however, show clearly that there is no significant relationship between board composition (ratio of outside directors on the board) and banks’ financial performance.</p>