According to regulations of Capital Market Board (CMB), Corporate Governance Principles Compliance Notes are given by independent rating institutions to companies whose shares are traded on Borsa İstanbul. Via those notes the 50 most successful companies on corporate governance are determined. In order to obtain indicators for the price and yield analysis, the 50 most successful shares are included in the Borsa İstanbul Corporate Governance Index. In this study with the exception of financial sector companies, financial performance ranking of 34 out of 50 companies of the Corporate Governance Index is performed by TOPSIS (Technique for Order Preference by Similarity to Ideal Solution) method. TOPSIS method was used based on the 10 financial ratios of the companies. 5 year performance rankings covering the years 2011-2015 were obtained and the ranking changes were examined. Finally, the 5-year average performance rankings were calculated and financial performance ratings of the companies in the index for 5 years is revealed.