The financial crisis and recurring corporate ethics scandals have strengthened the interest of policymakers, regulators and organizations in how to change the organizational culture to enhance ethical behavior and to prevent further disasters. For this purpose, solid measures are required that allow to assess the corporate ethical culture. Since there is an urgent need to have a German measure to promote research in German-speaking countries, this research developed and tested the German Ethical Culture Scale (GECS). Drawing on a prominent approach that has received much attention from scholars and practitioners alike, the GECS attempts to integrate the notion of compliance- and integrity-based ethics programs (with its focus on how to steer organizations) with the notion of ethical culture (with its focus on which factors inhibit or foster ethical behavior). Three studies with heterogeneous samples of German and Swiss employees and managers were conducted to develop, test and validate the multidimensional scale (total N > 2000). The studies provide first evidence of the measure’s construct, criterion-related and incremental validity. The paper concludes with a discussion of the strengths and weaknesses of the GECS, and implications for future research.