The aim of the paper is to study the theoretical aspects of corporate governance impact factors and to evaluate the impact of corporate governance on Return on Equity and Tobińs Q in Germany and Spain. The article focusses on analyzing the development of corporate governance in Germany as well as on a description of companýs success and of the investigated companies. Significant differences in the analyzed companies and in the country-specific corporate governance guidelines are highlighted. Literature review regarding previous results for the impact of corporate governance on companýs success in Germany, Spain and worldwide researches has been done. Tobińs Q and Return on Equity are introduced as the most used measures to deter-mine companýs success. Furthermore, the similarities and differences in the German and Spanish Corporate Governance Codes are assessed. The impact of Board size, Board Independency, Transparency and Directoŕs Remuneration as determents of corporate governance on Return on Equity and Tobińs Q as determents of companýs success is evaluated. A non-significant positive impact of all impact variables can be shown individually and combined in Germany and Spain. © 2018 International Social Science CouncilISSC. All rights reserved.