Corporate governance has emerged as a decisive business issue. Less corporate governance research is undertaken in civil law countries like Germany. In this thesis, the role of institutional investors in Germany is studied with the aim of providing an answer to the following research question: What role do independent institutional investors play in the corporate governance of listed German companies? This study follows an inductive qualitative research approach. The research model is based on six variables - board oversight, board nomination, identifying weaknesses, making recommendations, introducing changes in corporate strategy and exercising institutional power - to determine the role of institutional investors and to provide answers. Overall, the results show that the participants of the research study experience the role and responsibilities of institutional investors in the German two-tier corporate governance system as weak to medium across all six variables. The handling of recommendations from institutional investors to companies is not structured or executed in a systematic way by the study participants. The results indicate that the interviewees are convinced that institutional investors could be valuable partners in strengthening and improving corporate governance. They can play a role in corporate governance and can add value because they have a good understanding about the strategy and business model of the companies, expertise in research & analysis as well as a good sector expertise. However, the type of institutional investor matters in corporate governance. The strongest players are private equity and hedge funds. The weakest players are endowments and insurances. The most common company situations when institutional investors prompt change are underperformance, special companysituationsicrisis, corporate finance issues and management remuneration. The majority of the study participants expect a higher shareholder engagement in the future. Most of them have a positive point of view about the future role of institutional investors in corporate governance. III R The managerial implications of this study are that the investor relations function is well established and the programmes are sufficiently executed in German companies. Communication is the most appropriate measure. However, other typical and presumably more powerful measures like use of voting rights, engagement in the AGM, regular contact to the members of the supervisory board, taking a seat in the supervisory board, owning a meaningful company stake and collaboration with other shareholders seem to play a minor role. There is still potential for institutional investors to improve their role in corporate governance in German companies. In order to improve their influence in corporate governance institutional investors need to be prepared to pursue an escalation strategy. This encompasses for example to increase their stake to a meaningful and powerful level and/or they need to collaborate effectively and systematically with other shareholders to increase their acceptance vis-a-vis the company and to .ask for a seat in the supervisory board. However, such an approach also needs a strong long-term commitment and investment perspective as well as an attitude that also considers the long-term interests of the company. It can be concluded that institutional investors with a high level of expertise can contribute to the widely discussed improvement of the competence and independence of German supervisory boards. Important prerequisites of institutional investors to play a role in corporate governance are no conflict of interest and a sufficient sector expertise. Therefore, disadvantages like conflict of interest and lack of expertise have to be addressed properly. The results from this research can be used to draw lessons for (1) members of supervisory boards, members of the management board (in particular CEOs, and CFOs), as well as investor relations officers of listed companies, who want to improve governance and the relationship with their institutional shareholders; (2) institutional investors who want to enhance their engagement in their portfolio companies; and (3) standard setters like institutions and commissions that want to improve corporate governance.