This article is focused on the assisting role and gatekeeper function of the external auditor in the German two tier system. From on an agency-theoretical view, the auditor is part of the in- and external corporate governance. Conflicts of interests may arise from different tasks of the assisting role and gatekeeper function of the auditor, influencing the quality of the in- and external audit. Thus, future research is needed to provide theoretical foundation of the auditor’s assisting role for the benefit of the shareholders.