Proceedings of Annual Paris Economics, Finance and Business Conference 7 - 8 April 2016, Espace Vocation Haussmann, Paris, France ISBN: 978-1-925488-04-3 Board Structure and Firm Performance: Evidence from BIST 100 Companies in Turkey Mete Karayel1 and Mesut Doğan2 This study examines how board structure affects firm performance. Female directors, independent directors and foreigndirectors and board size were taken as the indicators of board structure. The empirical analysis, based on a sample of 100 firms drawn from the BIST 100 Index over a 3-year period, the years between 2012 and 2014. In the study, for financial performance indicators, Return on Assets, and Return on Equity were used and for market performance indicator Market Value to Book Value was used. After the analysis, it is found that, board structure has an impact on firm performance in BIST 100 companies. This study is unique in terms of analyzing the effects of 2012 regulation of mandating at least 1/3 of all board members to be independent directors and suggesting at least one female director to BIST 100 company boards by Capital Boards of Turkey. JEL Codes: G34, M14, L25. 1 Correspondant Author, Assist. Prof. Dr., AfyonKocatepe University, Faculty of Economics and Administrative Sciences, Department of (English) Business Administration Department, karayelmete@gmail.com, mkarayel@aku.edu.tr 2 Dr. AfyonKocatepe University, Bayat Vocational School, Department of Business Management, mesutdogan@aku.edu.tr